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UNIT VI REPRODUCTION Chapter 1 REPRODUCTION IN LIVING ORGANISMS CONCEPT MAP Reproduction Sexual Asexual Animals (Human) Plants Vegetative Propagation Plants Animals Androecium Male Gamete Gynoecium Female Gamete Zygote Plant "REPRODUCTIVE BIOLOGY" Sherman J. Silber, in vitro fertilization versus intracytoplasmic sperm injection Testes Ovary Sperm Ovum Zygote Animal FOREVIEW :  Reproduction is a biological process in which an organism gives rise to young ones . It enables the continuity of the species . EXPOSITION OF THE CONCEPTS REPRODUCTION Asexual Sexual 1. With or without involvement With involvement of gametes of Gametes 2. Single individual one or two parents 3. Morphologically, Genetically identical Differ from each other What are the differences between asexual and sexual method ? ASEXUAL REPRODUCTION Binary Fission Budding Zoospores Conidia Gemmules Example: Amoeba Paramoecium Yeast Hydra Fungi Algae Penicillium Sponges Plants – Vegetative Propagation Runner Rhizome Sucker Tuber Offset Bulb (Vegetative Propagules) bulbil Leaf Buds Sexual Reproduction Juvenile Phase in Animals Vegetative Phase in Plants Plants –Reproductive Phase (flowering) – Annual and Biennial - Vegetative and Reproductive phase clear. Perennial – Bamboo Strobilanthus kunthiana Animals - – - Once in their life time Once in 12 Years Reproductive Phase Egg laying animals Placental animals Primates - Birds Non – Primates – Oestrus cycle Menstrual cycle Seasonal Breeders Continuous breeders Events in Sexual Reproduction Pre – Fertilisation Fertilisation Post – Fertilisation What is gametogenesis ? Gametogenesis Gamete transfer Formation of Gametes Distinguish between homogametes and heterogametes Homogametes( Isogametes) Similar Gametes Eg. Cladophora Heterogametes Dissimilar Gametes Male Antherozoidor sperm Female Egg or Ovum Plants Bisexual Same Plant Homothallic or Monoecious Flower Male Flower Staminate Unisexual on different plants Heterothallic or Dioecious Name the gametes produced by staminate and pistillate flowers Female Flower Pistillate Monoecious –same plant Eg. Cucurbits, Coconut Dioecious –different plant Eg. Papaya, date palm Animals What are hermaphrodites? Bisexual (Hermaphrodites) Unisexual Both the sex organs Eg. Earth worm, Sponges tape worm, leech. Male or Female Eg. Cockroach Cell division during gamete formation Gametes – always haploid Mitosis Haploid (n) Parent Gametes Meiosis Diploid (2n) Gamete Gamete Transfer Male Gamete Motile Fungi, algae Both are motile Algae, Bryo, Pteridophytes - Female Gamete Stationary Water is the medium for transfer Number of male gametes more than female to compensate loss during transfer. Seed Plants How does cross pollination take place ? Pollen grains Ovule Male Gamete Egg Bisexual Eg: Peas - Self Pollination Unisexual - Cross Pollination Pollen Stigma Pollen tube formation Discharge of male gamete Dioecious animals – Special mechanism for gamete transfer. What is syngamy? Fertilisation Male gamete + female gamete (n) (n) Syngamy Zygote 2n Parthenogenesis : Female gamete develop into an organism without fertilization . Eg. Rotifers, honey bees, some lizards and birds ( turkey) Fertilisation External Fertilisation Internal Fertilisation External Medium Large no. of offsprings produced - Vulnerable to predators Inside the body Where does syngamy occur ? Post fertillisation events Zygote (2n) - First cell of the organism Universal in all sexually reproducing organisms Meiosis Zygote Haploid organism Mitosis Zygote Diploid organism Embryogenesis Zygote Mitosis Cell Division increase in no. of cells. Cell differentiation Specialised tissue and organs Animals Viviparous Zygote Oviparous Zygote – calcareous shell cover Inside the body Young ones Incubation Young ones hatched Delivered out Chances of survival is greater in viviparous – proper embryonic care and protection Why is the chances of survival is greater in viviparous ? Plants : Sepals, petals,stamens Zygote Ovule Ovary wither away embryo Seed Fruit Pericarp ( wall) after dispersal seed germinate into an organism. How are seeds and fruits are botanically referred to as ? -------------------------------- REVIEW TERMINOLOGY  Reproduction Menstrual cycle  Oestrus cycle Gametogenesis  Homogametes Heterogametes  Monoecious Dioecious  Unisexual Bisexual  Meiocytes Homothallic  Heterothallic Staminate  Pistillate Syngamy  Pollination Embryogenesis Questionnaire 1. What are vegetative propagation? 2. Differentiate between parthenocarpy and parthenogenesis . 3. Compare monoecious and dioecious . 4. Distinguish between the following: Oviparous and viviparous, External and internal fertilization, asexual and sexual reproduction . 5. The number of male gametes produced is several thousand times the number of female gamete produced. Why? 6. What are bisexual animals? Give any two examples. 7. What type of cell division does the haploid plant body will undergo during gamete formation? 8. What is embryogenesis? Chapter 2 SEXUAL REPRODUCTION IN FLOWERING PLANTS Chapter 2 SEXUAL REPRODUCTION IN FLOWERING PLANTS CONCEPT MAP Sexual Reproduction in Flowering Plants Female gamete Male gamete DOUBLE FERTILIZATION Embryo Endosperm FOREVIEW  Sexual reproduction in flowering plants involves transformation of diploid sporophytic cells into haploid gametophytic cells by meiosis.  Fusion of haploid gametes of opposite sex to form diploid Zygote.  The Zygote then develops into an embryo which ultimately forms a diploid plant body.  In flowering plants all these steps of sexual reproduction occur within specialized reproductive organs called the flowers. EXPOSITION OF THE CONCEPTS Sexual reproduction in Flowering Plants Flower (whorls) Sepals Petals Androecium Male Part Androecium Stamens Filament + Anther - bilobed Dithecous Gynoecium Female Part Transverse section of an anther Anther Four Microsporangia at the corners ( Pollen sacs ) Sporogenous tissue ( PMC) Meiosis Microsporogenesis Four wall Layers Epidermis Endothecium Protection middle layers Microspore tetrad tapetum - nourishes dissociate Microspores or Pollen grains Name the type of cell division does the PMC undergo to become microspores . Structure of the Pollen grains or Male Gametophyte 1. Two layered wall – outer hard layer , the exine made up of most resistant organic material Sporopollenin – resistant to high temperatrure, pH non enzymatic action. 2. Exine has an aperature, germ pore. 3. Inner wall is intine made up of cellulose and pectin 4. Cytoplasm of the pollen grain What is the significance of sporopollenin ? Mitosis Vegetative cell Generative cell Mitosis 2 Male Gametes What is the ill effect and usefulness of pollengrain to humans ? POLLEN GRAINS CAUSE ALLERGY POLLEN GRAINS ARE USED AS FOOD SUPPLEMENTS Female reproductive part, Gynoecium or Pistil Monocarpellary one carpel Multicarpellary many carpels Syncarpous Apocarpous Fused carpels free carpels Pistil has Stigma, Style, Ovary. Inside the ovary locule with placenta- ovules or megasporangia arising from placenta. Structure of an Ovule or Megasporangium The ovule has a stalk, funicle – hilum is junction between ovule and funicle – two integuments encircle the ovule except at micropyle opposite is chalaza. Enclosed is a mass of cells, nucellus with an embryo sac or female gametophyte. Megasporogenesis Nucellus (One cell enlarges) Megaspore mother cell Meiosis 4 Megaspores 3 degenerate, one functional megaspore nucleus divides mitotically 2 nucleate ( move to opposite poles ) II Mitosis 4 Nucleate III Mitosis 8 Nucleate Organised into Cells 3 Cells at Micropylar 3 cells at Chalaza Egg apparatus Antipodal cells Egg flanked by Synergids 2 Nuclei centre Polar nuclei Embryo sac Describe the structure of a mature embryo sac . Pollination Transfer of pollen grains from anther to stigma Autogamy Geitonogamy Same flower another flower of same plant Xenogamy different plants Eg. Oxalis, Commelina, Viola Chasmogamous Differentiate between geitonogamy and xenogamy . Cleistogamous Exposed anthers flower do not open Agents of Pollination Abiotic Biotic Bees, butterflies, flies, beetles,wasp ants, moths,birds,bats Wind Water Eg. Vallisneria, Hydrilla Zostera ( Marine Sea Grass) Characteristics of Wind Pollinated flowers 1. enormous amount of pollen 2. Pollen grains are light and non-sticky 3. Well – exposed stamens 4. Feathery stigma 5. Single ovule 6. Mostly inflorescence Eg. Corn cob, grasses not colourful no nectar Water Pollinated Flowers List out the characteristics of wind pollinated flowers . Insects Pollinated 1. Pollen grains have mucilaginous covering 2. Not coloured 1. Flowers are large 2. colourful 3. Fragrant 3. No nectar 4. Female flowers move to surface of water ,male flowers reach female 4. Rich in nectar 5. Foul odours to attract flies & beetles 6. Place to lay eggs Eg. Moth and plant Yucca. What are the devices developed by the flowering plants to encourage cross pollination? 1. Pollen release and stigma receptivity are not synchronised 2. Anther and Stigma are placed at different positions 3. Self – incompatibility 4. Production of Unisexual flowers Pollen tube growth in Stigma The pollen grains germinate- pollen tubes through germ pore grows through stigma, style, reaches ovary - enters ovule, through micropyle - enters through the synergids (filiform apparatus) - -two male gametes released Artificial hybridization is achieved by emasculation and bagging techniques( removal of anther and dusting stigma with anther of desired type ) DOUBLE FERTILISATION Male Gamete + Egg (n) (n) Syngamy Zygote (2n) Embryo triple Male Gamete + Polar Nuclei fusion n 2n Primary Endosperm nucleus 3n 3n Primary Endosperm cell Endosperm 3n Post – Fertilisation ENDOSPERM DEVELOPMENT What is double fertilization ? What is its significance ? PEN undergoes repeated nuclear division to form free – nuclear endosperm – cell wall formation occurs to become cellular – triploid tissue with nutrients for developing embryo. Endosperm Completely consumed Eg: Peas, beans Persist Eg. caster, coconut Embryo Development ( Embryogeny) Zygote Pro embryo Globular embryo Heart shaped embryo Matured embryo Dicot Embryo Two Cotyledons Embryonal axis above cotyledons Epicotyl + plumule Below cotyledons hypocotyl + radicle Monocot Embryo One cotyledon ( Scutellum) one side of the embryonal axis – lower end radicle with root cap enclosed by coleorrhiza – above the attachment of scutellum is epicotyl has shoot apex, leaf primordia enclosed in coleoptile. Describe the structure of a monocot embryo . Seed ( Fertilised Ovule) Seed coat Cotyledon Storage of food reserve Embryonal axis Seeds Non – albuminous endosperm consumed during embryo development Eg. Pea, ground nut Albuminous endosperm not completely consumed Eg. wheat, maize, barley caster, sunflower Black Pepper Residual, Persistent ,nucellus – perisperm Integuments Seed coat with micropyle for entry of oxygen and water during germination embryo is dormant till favourable conditions. Fruit ( Ripened Ovary) Ovary Wall Pericarp Fleshy Guava, Orange mango Dry Ground nut mustard Fruits False Fruit thalamus becomes fruit Apple, strawberry cashew True Fruit ovary becomes fruit Mango Differentiate between false and true fruit . PARTHENOCARPIC FRUITS – FRUITS DEVELOP WITHOUT FERTILIZATION. EG. BANANA. IMPORTANCE OF SEEDS 1. 2. 3. 4. 5. Dispersal to new habitat Nourishing young seedling Protection to embryo Leads to Variation Storage of Seeds – seed bank Apomixis ( Seed production without fertilization) What is Diploid egg cell Embryo parthenocarpy? Nucellus Embryo Polyembryony – More than one embryo in a seed. REVIEW TERMINOLOGY Microsporogenesis Megasporogenesis Sporopollenin Embryosac Syncarpous Apocarpous Autogamy Geitonogamy Xenogamy Double fertilisation Endosperm Parthenocarpy QUESTIONAIRE 1. What develops into a microspore mother cell in a flower? Trace the development of this cell into a pollen grain which is ready for germination. Draw a labeled figure of a mature pollen grain. 2. Draw a L.S of a flower showing the growth of a pollen tube. 3. Draw a L.S. of a maize grain to show the structure of mature embryo. 4. Write the characters of insect pollinated flowers. 5. What are the characteristics of a wind pollinated flowers? 6. Trace the development of a mature ovule from a megaspore mother cell/ 7. What is double fertilization? Explain. 8. Differentiate between monoecious and dioecious plants. Give an example of each. -------------------------------------- Chapter 3 HUMAN REPRODUCTION CONCEPT MAP Reproduction in Humans Female Ovaries ovum Male Testis Sperm Fertilization Zygote Embryonic development Reproductive Cycle FOREVIEW  Human are sexually reproducing and viviparous  Reproductive events include  Gametogenesis  Insemination  Fertilisation  Implantation  Gestation  Parturition What do you mean by viviparous? What is fertilization? EXPOSITION OF THE CONCEPTS Male reproductive system 1. A pair of testes 2. Accessory ducts 3. Glands 4. External genitalia Testes in scrotum lower the temperature necessary for spermatogenesis. Testicular lobules Seminiferous tubules Male germ cells ( Sperm formation) and Sertoli cells ( nutrition) – Interstitial or Leydig cells ( Hormones) Accessary ducts include rete Testis epididymis ejaculatory duct Vasa eferentia Vas deferens urethra Seminal vesicle Penis Urethral meatus Accessory Glands Paired seminal vesicle ,prostate glands bulbourethral glands Seminal fluid & sperm - semen Female Reproductive System 1. A pair of ovaries 2. Pair of oviducts 3. Uterus Accessory ducts 4. Cervix 5. Vagina 6. External genitalia 7. Accessary Glands - Mammary glands Ovary Thin epithelium cover Stroma into two zones cortex and medulla- oviduct funnel – shaped in fundibulum, finger – like projections fimbriae ampulla isthmus. Uterus has an outer perimetrium, middle myometrium, inner endometrium Uterus cervical canal Vagina External genitalia includes mons pubis, labia majora, labia minora, hymen and clitoris. Glandular tissue Mammary gland Mammary lobes with alveoli Mammary tubules Mammary duct Lactiferous duct Gametogenesis - Formation of gametes Spermatogenesis Spermatogonia Oogenesis Mitosis differentiation Primary Spermatocytes Meiosis I Secondary Spermatocytes Meiosis II Spermatids Spermiogenesis Differentiation Explain the hormonal control of spermatogenesis . Spermatozoa Hormonal Control GnRH ( Hypothalamus) LH Leydig cell FSH Sertoli cell Anterior Pituitary ( LH and FSH) Androgen spermatogenesis Factors help in Spermiogenesis Structure of a Sperm Head Middle piece Acrosome, nucleus Mitochondria Tail Oogenesis [ Formation of Ovum] Oogonia Foetal life Mitosis differentiation Prophase I completed Primary Follicle Primary Oocyte Sec. Follicle birth Meiosis I Meiosis I tertiary follicle Completed Secondary Oocyte Puberty Ovulation Meiosis II (Only after the entry of sperm) Polar body Second polar Body Polar Body Graafian follicle surrounded by Zona pellucida Menstrual Cycle Menarche Menstrual cycle Adult reproductive life Ovum Differentiate between oogenesis and spermatogenesis . Menopause Menstrual Phase 3 – 5 days Breaking of endometrial lining of the uterus and its blood vessels Menstural flow I II Follicular Phase ( Proliferative Phase) Ovary - Primary Follicle Grows Graafian follicles Uterus : Proliferation of endometrium of Uterus Ovulatory Phase 14th day Release of Ovum – Ovulation Graafian follicle transformed into– Corpus luteum Luteal Phase ( Secretory Phase) Ovary – no growth of follicles Uterus – Preparation of endometrium for implantation In case of fertilization other events of pregnancy In the absence of fertilization corpus luteum degenerates – disintegration of endometrium menstruation Hormonal Control of menstrual cycle I Follicular phase LH – Follicular development FSH and secretion of estrogen Explain the hormones controlling menstrual cycle . II Ovulatory Phase LH and FSH – Peak level III Luteal Phase Corpus luteum – Progesterone – maintenance of endometrium Fertilisation Fusion of ovum and sperm at ampullary- isthmic junction of fallopian tube. Entry of Sperm into egg Acrosome secretions into the egg . corona radiata – Zona pellucida – sperm entry Egg – II Meiosis of secondary oocyte – ovum is produced – fusion of sperm nucleus and ovum – Zygote. Sex Determination Female XX Gametes Male XY X X XX Female Y XY Male Explain that the sex of the baby is determined by the father not by the mother Implantation Zygote Cleavage Morula Blastomeres Blastocyst Tropho blast ( Outer layer) Inner Cell mass Embryo Attached to endometrium uterine cells divide rapidly Leads to pregnancy Pregnancy Trophoblast – fingers – like projections, chorionic villi – interdigitated with uterine tissue Placenta Functions of Placenta 1. Supply of Oxygen and nutrients 2. removal of carbon – di – oxide and waste materials List out the functions of Placenta Umbilical cord - transport of substances to and from the embryo Hormones secreted by Placenta are Human Chorionic Gonadotropin, Human placental Lactogen, Estrogen , Progestogens Relaxin (ovary) – essential for foetal growth, changes in mother, maintenance of pregnancy. Ectoderm Endoderm Mesoderm Inner Cell Mass Tissue Organs Embryonic development during pregnancy [ Gestation Period ] I Month end of II Month end of III Month V Month - - end of VI Month end of IX month - Heart Limbs and digits Major organ systems – Genital organs Movement of foetus appearance of hair on head Fine hair on body, eye-lids separate, eye lashes fully developed What are the Major features of embryonic development at various months of pregnancy? Parturition – Child Birth Foetal ejection reflex from foetus and Placenta / Oxytocin Secretion Uterine Contraction expulsion of baby with placenta Name the injection given by the doctor to induce delivery Lactation Production of milk by the mammary glands at the end of pregnancy – to feed new born Colostrum – first milk after delivery – contains antibodies, gives resistance to new born. What is colostrum? What is its importance? ----------------------------------- REVIEW TERMINOLOGY Spermiogenesis Oogenesis Fertilisation Parturition Lactation Blastocyst Endometrium Leydig cells Spermatogenesis Ovulation Implantation Colostrum Placenta Corpus luteum Sertoli cells Seminiferous tubules QUESTIONNAIRE 1. Draw a flow-chart showing hormonal control of human female reproductive system. 2. Describe spermatogenesis in humans . 3. Draw a diagrammatic sectional view of the human female reproductive system . 4. Describe the structure of a sperm . 5. Draw a neat labelled sketch of a sperm . 6. Draw a neat labelled sketch of the following : a. Diagrammatic sectional view of a seminiferous tubule (enlarged ) . b. Diagrammatic sectional view of ovary . c. Structure of an ovum . 7. Describe oogenesis in human female . What promotes completion of second meiotic division in oogenesis ? 8. What are the hormones secreted by human placenta ? 9. What is the role of Sertoli cells and Leydig cells ? 10. Name the male accessory glands . 11. What is corpus luteum ? What is its role ? Chapter 4 REPRODUCTIVE HEALTH CONCEPT MAP Chemical Surgical Birth Control Mechanical Reproductive Health STD’s FOREVIEW  Reproductive health – What do you understand by this term?  It is the total well – being in all aspects of reproduction – Physical, emotional, behavioural, social EXPOSITION OF THE CONCEPTS Problem and Strategies  Family Planning initiated in 1951  Reproductive and Child Health care (RCH) programmes 1. Creating awareness 2. Providing facilities 3. Support  Awareness about reproduction related aspects taken up by NGO and Government  Educating people about reproductive organs, STD, AIDS, Birth control options, care of pregnant mothers, post – natal care, breast feeding, population growth. equal opportunities for male and female child, social evils.  Amniocentesis – banned for female foeticides POPULATION EXPLOSION AND BIRTH CONTROL Reasons for population explosion What are the reasons for 1. Decline in death rate maternal mortality rate population Explosion? 2. Infant mortality rate What is its effect? 3. Increase in people of reproducible age Effect 1. Scarcity of food, shelter, clothing etc List out the methods of Birth Control Control 1. Contraceptive methods 2. Marriageable age increased 18 years for female , 21 years for male 3. Incentives given to couples with small families. Contraceptive should be user – friendly, easily available, effective, no side effects, not interfering with sexual desire. Contraceptive methods 1. Natural / Traditional [ avoiding ovum and sperm meeting] a. Periodic abstinence b. Withdrawal or coitus interruptus c. Lactational Amenorrhea 2. Barrier [ Ovum and Sperm are prevented from meeting ] a. Condoms - Male and female b. Diaphragms c. Cervical caps Female Which Contraceptive d. Vaults method is ideal for e. Spermicidal creams, jellies, foams females? 3. IUDs a. b. c. – Intra uterine devices ( ideal for females) Non – medicated IUDs eg. Lippes loop Copper releasing IUDs CuT, CuT Multi load 375 Hormone releasing IUDs Eg. Progestasert LNG – 20 IUDs increase phagocytosis of sperms in uterus Cu ions suppress sperm motility and fertilizing capacity Hormone releasing IUD’s make uterus unsuitable for implantation 4. Oral Contraceptives Progesteron or progesterone – estrogen combination as pills – inhibits ovulation implantation, quality of cervical mucus to prevent entry of sperms. 5. Injections Progesteron or with estrogen 6. Implants under the skin Surgical Method or Sterilization It blocks gamete transport Vasectomy in male Tubectomy in female Medical Termination of Pregnancy ( MTP) International or voluntary termination of pregnancy before full term is MTP or induced abortion. Sexually Transmitted Diseases ( STDs) Diseases transmitted through sexual inter course is STD or VD or RTI Gonorrhoea, Syphilis, Genital herpes, Chlamydiasis, Genital warts, trichomoniasis hepatitis B, HIV Mode of Spread 1. 2. 3. 4. 5. Injection needles What are STDs . Surgical instruments of Infected Persons How does it spread. Transfusion of blood infected mother to foetus Hepatitis B, Genital herpes, HIV – can’t be cured Symptoms Itching, fluid discharge, slight pain, swellings in genital region Complications Pelvic inflammatory diseases abortion still births ectopic pregnancy infertility Cancer INFERTILITY Reason Physical, congenital, disease, drug immunological, psychological Assisted reproductive Technologies (ART) In vitro fertilization Embryo transfer Test tube baby programme – fusion of the gametes outside – ZIFT - Zygote intra fallopian transfer or IUT Intra uterine transfer In – vivo fertilization ( Fusion of Gametes within female) GIFT – Gamete intra fallopian transfer ICSI – Intra cytoplasmic sperm injection AI - Artificial insemination IUI - Intra uterine insemination REVIEW TERMINOLOGY & ABBREVIATIONS Amniocentesis Mortality IUDs Sterilisation MTP STD Infertility Artificial insemination In-vitro fertilization In-vivo fertilization QUESTIONS 1. What are the reasons for population growth and what is its effect ? 2. Mention the different categories of contraceptive methods . 3. Which contraceptive is ideal for female ? How does it help in birth control ? 4. Differentiate between vasectomy and tubectomy . 5. Mention five sexually transmitted diseases . 6. Write any two STDs which can’t be cured even at the initial stage . 7. Explain how STDs are transmitted . What are its symptoms ? 8. Expand the following abbreviations . ART ,ZIFT ,GIFT ,IUI ,IVF ,MTP ,ICSI ,PID 9. Explain the types of barriers which prevent the physical meeting of sperm and ovum . --------------------- Unit – 7 Genetics and evolution Chapter 5 Principles of Inheritance & Variation Mendel’s Law of Inheritance Mutation Chromo somal Disorder s Inheritan ce of Two gene Genetic Disorders PhenylKetonuria Down’s Syndro me Inheritance of one gene Klinefelter’s Syndrome Hemoph -ilia Turner’s Syndrome Linkage Gregor Johaan Mendel Father of Genetics Sickle cell Anemia Incomplete Dominance Chromosomal Theory of Inheritance Recombination Sex determination Codominan ce PRINCIPLES OF INHERITANCE AND VARIATION 1. Fore View 2. Exposition of the Concepts  Heredity  Mendel’s Laws of Inheritance  Inheritance of one gene  Inheritance of two gene  Chromosomal theory of inheritance  Sex determination  Mutation  Genetic disorders (i) Pedigree analysis (ii) Mendelian disorders (iii) Haemophilia Sickle Cell anemia Phenyl Ketonuria (iv) Chromosomal Disorders Down ’s syndrome Klinefelter’s syndrome Turner’s syndrome 3. Review / Summary 4. Terminology 5. Questionnaire FORE VIEW  ‘Like begets like’ is a long known phenomenon and explains that living things tend to produce off springs that resemble them.  Children tend to resemble their parents, grand parents, grandgrand parents.  You must have heard casual remark as ‘he is carbon copy of his father’ or he has fathers nose or grandfather’s eyes or she has mother’s complexion.  The ancient Greeks believe that blue-eyed parents have blueeyed children; that baldness and squint eyes follow in successive generations; that certain eye defects run in particular families.  This passage of characters from one generation to next is called Heredity or inheritance.  Though the off springs resemble their parents, they are not identical.  They usually differ among themselves and also from their parents.  Except for identical twins, no two siblings or brothers and sisters show close resemblance.  Differences among individuals of species are called variations.  There are two types of variations i.e. environmental variation; are due to food, temperature or other external factors. Hereditary variations are due to genetic or genetic difference.  HERIDITY Heredity may be defined as the transmission of characters in living beings from one generation to successive generations.  GENETICS Genetics is that branch of biological science which deals with the mechanism of transmission of characters from parents to off springs. The word genetics is derived from Greek word ‘gen’, meaning to grow or to become . EXPOSITION OF CONCEPTS  MENDEL’S LAWS OF INHERITANCE SYMBOLS AND TERMINOLOGY (i) Symbols Mendel used English alphabets to represent the factors. The first letter of the dominant character is often used to designate the character. Its capital letter as ‘T’ for tallness represents the dominant character and small letter ‘t’ represent recessive character (dwarfness) TERMINOLOGY  Gene Mendel presumed that a character is determined by a pair of factors or determiners present in each cell of the individual called as genes.  Genotype and Phenotype Genotype designates the genetic make up of an organism, whereas phenotype is used to indicate the external appearance of an individual.  Homozygous and Hetrozygous Every organism possesses two alleles for every character. In an organism the two alleles for a particular character or identical called Pure homozygous. TT or tt . Heterozygous receives two different alleles for the same character from its two parents Tt.  Allele It refers to one member of a gene pair (alternative forms of the same gene. Each character has two determiners called factors. If the factors represent the extremes or alternatives of the character they are called alleles).  Dominant and Recessive The gene which gains expression in F1 hybrid is known as dominant gene. The gene which is unable to express itself in presence of the dominant gene is the recessive gene.  Monohybrid Cross It involves the study of inheritance of single pairs of contrasting characters Eg: Inheritance of tall and dwarf characters or yellow and green colour of seed cotyledon.  Dihybrid Cross It involves the study of inheritance of two pairs of contrasting characters. Eg Inheritance of yellow and round seed character and green wrinkled character.  Test Cross A cross between hetrozygous F1 hybrid and the double recessive homozygous.  Back Cross A cross between F1 hybrid with either of the two parents of P1 generation. Why Mendel did experimental material? selected Garden pea as his Reasons of Mendel Success:  Statistical analysis  Mathematical logic  Scientific aptitude  Combination of luck & Foresight  MENDELS LAWS OF INHERITANCE Mendel's noted that the hybrid off springs invariably resembled one parent; the character which appeared in F1 generation was called dominant and one that remained hidden was called recessive. Mendel formulated two laws (i) LAW OF SEGREGATION Paired factors responsible for a character segregate into gametes and are recombined at fertilization. Yellow 0+ 0 Y y Y YY Yellow Yy yellow y Yy yellow yy yellow F2 Phenotype = 3:1 Genotype = 1: 2 : 1 Mendelian ratio for monohybrid cross is 3:1 In the above cross, we see that every individual has two factors (YY, Yy, yy) for the seed colour. When gametes are formed each gamete carries only one factor for a character. It means that gametes. are always pure. Since the gametes always contain one factor for a character. It is also called law of purity of gametes. (ii) LAW OF INDEPENDENT ASSORTMENT “Segregation of one pair of factor is independent of the segregation of other pair of factor”. It is also called as di-hybrid cross. 0+ 0 RY Yr yR yr Ry RRYY RyYY RYyR RrYy Yr RyYY rrYY RrYy rrYy yR RYyr RyYr yyRR yRyr yr RyYy Yyr yRyr rryy Mendelian ratio of dihybrid ratio = 9 : 3: 3: 1 In the above experiment we see that yellow colours occur with round seeds and green colour occurs with winkled seeds. In F 1 all progeny having yellow colour of round seeds indicating that yellow colour in dominant over green colour and round shape dominant over wrinkled shape. But in F2 generation yellow colour occurs both in round and wrinkled seeds. Similarly round seeds may be yellow or green. It proves that one pair of factors assorts independent of the other pair of factors.  Test cross The back cross between F1 individual and the recessive parent is called test cross. Because it is used to test whether an individual in Homozygous or Heterozygous Back Cross A cross between F1 individual with either of the parent is called back cross Gametes Ratio 1:1  Incomplete Dominance When two alleles of a pair interact and produce an intermediate phenotype. Eg : Snapdragon (Antirrhinum majus) A cross between Red flowered and white flowered variety produces all Pink F1 Progeny. This type of inheritance is called incomplete dominance. F1 plants an self produce it gives red : Pink : White i.e. 1 : 2 : 1. It again shows that characters do not blend and are discrete. R RR Red Rr Pink R r r Rr Pink rr White Co-dominance In Co-dominance the F1 generation resembles both parents Eg : ABO Blood grouping in human beings ABO blood group are controlled by ‘I’ gene.  Multiple alleles When more than two i.e., three alleles governing the same character are called multiple alleles. Chromosomal theory of inheritance It was given by Sutton and Boveri in 1902. It states that (i) Mendelian factors or genes are located on the chromosomes (ii) It is the chromosomes independently. that segregate and assort  Chromosomal theory of inheritance was proved by T.H.Morgan and his colleagues led to discovering the basis for the variations and sexual reproduction.  T.H.Morgan worked with tiny fruit flies. i.e. (Drosophila melanogaster)  Linkage The tendency of the genes remain in their parental combination is called linkage. Genes occurring on one chromosome is called linkage group.  Recombination The generation of non-parental gene combinations is called recombination. SEX DETERMINATION IN HUMANS In humans 23 pairs of chromosomes are present. Out of these 22 pairs are called auto some; and other one pair is called sex chromosome. i.e., male XY and female XX. After fertilization, the genetic make up is shown as below. It is evident that it is the genetic make up of the sperm that determines the sex of the child.  Mutation Mutation is a phenomenon which results in alteration of DNA sequences and results in the changes in genotypes and phenotypes OR “Sudden changes that takes place in the genetic material  Mutagens The substances that cause mutation are known as mutagens. Eg : X-rays, UV rays, ß rays etc. GENETIC DISORDERS PEDIGREE ANALYSIS Advantages  To provide a strong tool and to trace the inheritance of a specific trait; Abnormality or diseases.  To define the history of a character in a family. SYMBOLS COMMONLY USED IN PEDIGREE CHART  Mendelian Disorders Most common Mendelian disorders are (i) Haemophilia (ii) Cystic fibrosis (iii) Sickle Cell Anaemia (iv) Colour blindness (v) Phenyl Ketonuria (vi) Thalassemia  Haemophilia o It is also called Bleeders disease. o It is due to mutant genes located on 'X' chromosomes. o It is more common in males as they have only single X chromosome.  Sickle Cell Anaemia o It is an auto some linked recessive trait. o Sickle Cell person with the genotype of HbsHbs. o Patient dies due to damaged heart, kidney, spleen and brain. o Person with heterozygous genotype HbAHbs are said to be Carriers.  Phenyl Ketonuria o In born errors of metabolism o Autosomal recessive trait o Affected person lacks an enzyme that converts the amino acid Phenyl analine in to tyrosine.  Thalassemia o Erythroblastic anaemia due to homozygous recessive gene expression in children. o Person shows decrease in bone marrow cavity. o Enlargement of spleen. o Enlarged liver.  Chromosomal Disorders The chromosomal disorders are caused due to absence or excess or abnormal arrangement of one or more chromosomes.  Aneuploidy Failure of segregation of chromatids during cell division cycle results in the gain or loss of chromosomes called aneuploidy.  Polyploidy Failure of cytokinesis after telophase stage of cell division results in an increase in a whole set of chromosome in an organism called Polyploidy  Down syndrome o It is an autosomal abnormalities o It is caused due to presence of extra 21 chromosome (Trisomy) arises by non disjunction during egg cell formation. Symptoms  Prominent forehead  Open mouth  Protruding lower lip  Under developed genetalia  Klinefelters Syndrome o It is a sex chromosomal abnormalities o It takes place among male having XXY Sex-chromosome. Symptoms  Sterile  Under developed testis.  Enlarged breasts  Sparse body hair.  Turner's Syndrome o It is a sex chromosomal abnormalities o Absence of one 'X' Chromosomes i.s. 45 + XO o Takes place among females. Symptoms  Sterile  Ovaries are rudimentary  Lack of other Secondary sexual characters. Chromosomal Disorder Aneu Ploidy 1. Autosomal Abnormalities Poly ploidy Down's syndrome 2. Sex chromosomal Abnormalities Klenfelters syndrome 45 + XXY♂ Turner's Syndrome. 45 + X♀ REVIEW / SUMMARY  Genetics is a branch of biology that deals with principles of inheritance and its variation  Mendel first studied this phenomenon systematically  He proposed factors regulating the characters.  Hence characters segregate while formation of gametes.  Mendel's law extended in the form of chromosomal theory of inheritance (Sutton and Boveri)  Chromosomes are two types i.e. Auto some and sex chromosome.  It brings sex determination  Mutation makes sudden change in the genetic make up.  Inheritance of mutation can be studied by pedigree Analysis.  Some mutation involves change in whole set of chromosome.  It can also studied by analysis of Karyotype. Terminology  Homozygous  Phenyl Ketonuria  Heterozygous  Klinefelter’s syndrome  Linkage  Down's syndrome  Recombination  Turners Syndrome  Heterogamete  Mono hybrid cross  Mutation  Dihybrid Cross  Mutagens  Test Cross  Bleeder's disease  Back Cross  Haemophilia  Aneuploidy  Sickle cell Anaemia.  Polyploidy QUESTIONNAIRE One mark each 1. What is emasculation? 2. What are alleles? 3. Mendel's factors are known by a new name now-a-days. What is it? 4. Name the plant on which Mendel worked? 5. What do the symbols square and circle in pedigree chart indicate? 6. Define and design a test cross. 7. What is point mutation? 8. Write any two advantages of pedigree analysis? 9. What is mutagens ? Give any two examples. 10. Name the gene responsible for sickle cell anemia. Two marks questions 11. What is clone? How does it differ from offspring? 12. State and explain law of segregation? 13. Differentiate between test cross and reciprocal cross. 14. Hemophilia victims are mostly men. Very rarely women are affected by it. Why is it so? 15. What is Klienfilters syndrome? Write its characters. 16. Draw pedigree chart and write its symbols Three marks questions 17. State and explain law of independent assortment with the help of a Punnet square board. 18. What is meant by incomplete dominance? Cite one example and explain it. 19. Explain the following terms. a. Phenyl Ketonuria b. Down's Syndrome c. Turner's syndrome. 20. Define a. Homozygous b. Heterozygous c. Genotype d. Phenotype e. Dominant f. Recessive Five mark each 21. A man with AB blood group has married a woman with O group. Show all the possible genotypes and phenotypes of the progeny. 22. Explain the law of dominance using a monohybrid cross. 23. How is sex determined in human beings? Chapter 6 MOLECULAR BASIS OF INHERITANCE CONCEPT MAP Contents (i) Fore View (ii) Exposition of the Concepts  Structure of DNA Polynucleotide chain  Double helical structure of DNA  DNA is a Genetic material a. Fredrick Griffth expt. b. Hershey & Chase Expt. c. Properties of DNA  DNA Replication a. Messelson & Stahl's Experiment b. Enzymes involved in replication c. Transcription d. Process of Transcription  Genetic code  Structure of RNA a. Structure of tRNA  Regulation of gene expression a. Lac operation model  Human Genome project  Goals of HGP  Applications of HGP  DNA - Finger Printing (iii) Review / Summary (iv) Terminology (v) Questionnaire FORE VIEW  Chromosomes are the carriers of genetic material.  Chromosome contains proteins DNA and RNA.  It is universally accepted that DNA is the genetic material in most of the organisms.  In most of the plant viruses, RNA is the genetic material.  There are many direct evidences for DNA being the genetic material.  These genetic materials contain the information for cell structure, function and reproduction in stable form.  DNA can also replicate the same information in the descendent cells and in successive generations.  Information coded in the genetic material could be decoded to produce molecules essential for structure and functions of cell.  Genetic material must be capable of in frequent variations that could be stably inherited. EXPOSITION OF THE CONCEPTS DNA (De oxy Ribo nucleic Acid) DNA is foundries in the cells of all living organisms except in plant viruses. In Eukaryote cells it is confined to the nucleus; where in association with proteins it forms nuclear proteins or the chromatin material. In prokaryotes DNA lies naked and free in the cytoplasm in the nucleoid region. Structure of DNA DNA is an acidic substance present in nucleus was first identified by Friedrich Meischer in 1869. DNA is a long polymer of deoxyribonucleic tides. Length of DNA is defined as the number of nucleotides present in it. A nucleotide has three components’, a nitrogenous base, Pentose sugar and a phosphate Group. There are two types of nitrogenous bases are Purine & Pyrimidines. Purines (Adenine & Guanine) Pyrimidines (Cytosine, Uracil & Thymine) Cytosine is common for both DNA and RNA Uracil is present in RNA only. Nitrogenous base is linked to the pentose sugar with glycosidic linkage and called nucleoside When phosphate group is linked to 5'-OH of a nucleoside to form nucleotide Double Helical structure of DNA  It is made up of two polynucleotide chains  Both chains run in anti parallel direction i.e. 5' --> 3' & 3' - 5'.  The nitrogenous bases in two strands are paired through Hydrogen bonds.  The distance between the two strand is 3.4 nm.  The width of DNA molecule is 20Ao.  The strands completes a turn every 34Ao along its length.  Each strand has nitrogenous base, Pentose sugar and Phosphate group. Base Paring rule DNA is a genetic material  DNA is a genetic material. It can transfer the characters from parent to offspring.  The transformation takes place through the molecules which contain nitrogenous base, pentose sugar molecule and phosphate molecule. In 1928 Friedrich Griffith found that pneumonia causing bacteria in two forms and was explained as follows.  Bacterial Transformation o 1928, the bacteriologist Fredric Griffith conducted an experiment on streptococcus pneumonia o He studied two stains of virulent streptococcus causing pneumonia. o The virulent strain synthesized a smooth Poly saccharine coat and produces smooth colonies. This strain was called strain-S o Another strain which lacked the proper protein coat is harmless and produces - rough colonies. This strain was called strain-R Griffith conducted the experiment as follows. (i) 'S' type injected (ii) ‘R’ type injected (iii) ‘S’ type injected Suffering  Mice die Pneumonia No Suffering  Mice live No Suffering  Mice live (Heat killed) (iv) ‘S’ type Heat killed injected + ‘R’ type Suffering  Mice die pneumonia Conclusion He concluded that the R-strain bacteria had been transformed by the heat killed S-strain bacteria. Some heat killed ‘S’ type enabled the ‘R’ type to synthesize polysaccharide coat and become virulent. This may be transform of genetic material. Biochemical characterization of transformation. Principle was explained by O. Avery:C. MacLeod and Maclyn Mc carty. (1933 – 44)  Bacterial Transduction method OR Hershay and chase method o DNA is the carrier of genetic material is shown by the study of viruses which infect bacteria. These are known as bacterio phages. o A.D. Hershey and M.J.Chase 1952conducted experiment on T2-phage a parasite on common bacterium called E Coli to demonstrate that its DNA carries the genetic information. o Some phages were grown in bacterium containing radio active sulphur – S35. Sulphur is incorporated in the formation of amino –acids – cysteine and methionine. o Some other phages were grown in bacteria containing radio active isotope phosphorous – P32. Phosphorous is an important constituent of DNA. o These two types were made to infect normal bacteria in two separate samples. o The protein coat were separated from bacterial cell by centrifugation. o Bacteria which were infected with viruses that had radio active DNA. o Bacteria that were infected with viruses that had radio active proteins were not radio active. This indicates that proteins did not enter the bacteria from the viruses. Properties of DNA verses RNA DNA  It contains a 5c deoxy RNA It contains 5c Sugar ribose ribose  It contains Adenine Guanine, cytosine & Thymine  Mostly occurs as a double It contains Adenine Guanine Cytosine and Uracil. Occurs as single stranded stranded helix.  It is often much longer.  It is more stable and resistant to enzymatic action. It is shorter. It is less stable and not resistant to enzymatic actions. REPLICATION OF DNA One of the active functions of DNA is to make its copies which are transmitted to the daughter cells.  Replication is the process by which DNA makes exact copies of itself.  Replication is the basis of life and takes place during the inter phase stage.  Watson and Crick suggested the semi conservative method of replication of DNA.  This has been proved by Messelson and stahl’s is E.Cols. REPLICATION OF DNA BY SEMI CONRSERVATIVE METHOD. Messelson & Stahl’s Experiment (1958)  In 1958 Meselson & Stahl cultured a species of bacteria (E.Coli) in a cultural medium containing 15N isotopes of nitrogen.  After these had replicated for a few generations in that medium both the strands of their DNA contained 15N as constituent of purines and pyrimidines.  Again it was transferred to with culture medium with 14N and found that; DNA separated into Ist generation having one strand heavier and the other.  The heavier strand represents parental strand and the higher one is newly synthesized DNA.  Here each daughter molecule has one strand – from the parent molecule and another synthesized a new – This property of DNA is called semi-conservative nature. PROCESS OF REPLICATION OVERALL DIRECTION OF DNA REPLICATION During DNA replication the following changes takes place due to the activation of the following enzymes.  Helicases : To unwind the DNA helix.  Topoisomerase: To break and reseal strands of DNA which serves as starting points for replication.  Primase : To Synthesize DNA Primer. It is the starting block of any DNA synthesis.  DNA Polymerase : Polymerizes nucleotides in an orderly and desired fashion.  DNA ligase : Joining small okazaki fragments removing Primers. Central Dogma DNA  RNA  Proteins The unidirectional flow of information from DNA leading to the synthesis of proteins called “Central dogma” Transcription The Process by which copying genetic information from one strand of the DNA is to RNA is termed as transcription. A transcription unit in DNA is defined primarily by the three regions in the DNA (i) Promoter (ii) The structural gene (iii) A terminator A hypothetical sequence from a transcription unit is represented as below. 3’ – A T G C A G C T A G C A T G C – 5’ 5’ – T A C G T C G A T C G T A C G – 3’ TRANSCRIPTION UNIT AND THE GENE Gene : A gene is defined as the functional unit of inheritance. Cistron : A segment of DNA coding for polypeptide called exon. Intron : Unwanted RNA regions or interversing sequences do not appear in mature. PROCESS OF TRANSCRIPTION  During the process of transcription the RNA plays the major role. The types of RNA’s and their function as follows. mRNA : It provides template tRNA : It brigs amino acids and reads genetic code. rRNA : It plays structural and catalytic role during translation.  The linear sequence of nitrogenous bases A, U, C, G on mRNA can be convey the message of DNA; if three letters are read together is called codon.  Each code signifies an amino acid.  AA + ATP Amino acetyl . AA – AMP – Enzyme’ + PPi tRNA Synthesize  AA – AMP – Enzyme – t – RNA  AA + tRNA + Enzyme +AMP Here amino acids has to be activated by ATP before it makes a complex with its specific carrier. Translations It occurs in three steps (i) Initiation The m-RNA at 5’ end binds to the small sub-unit of ribosomes. It is brought about by base pair formation between certain sequences on their r-RNA and m-RNA. (ii) Elongations A second t-RNA charged with an amino acid now forms hydrogen bonds – with the second codon on the m-RNA. The second amino acetyl-tRNA comes to a site A near the site P on the ribosome. (iii) Termination Chain formation comes to a stop as soon as any one of the three non-sense codon comes (UAA, UGA, UAG). Since no amino acids codes for these codon; it is a signal for the chain to drop out. It is called chain termination. “Diagram showing Process of transcription in Eukaryotics”.  Eukaryotic genes are more complex than the prokaryotes.  The information on an eukaryotic gene for assembling a protein is not continuous but split.  When m-RNA is formed from such genes, the unwanted RNA region <Intone> are removed and the region coding for amino acids.  Exons are joined together. It is called splicing. GENETIC CODE CODONS A particular sequence of three bases <triplet> would code for a particular amino acid and this triplet is referred to as codon. Singlet Code : Simplest possible code i.e. code of a single letter Eg: A,U,G Doublet Code : a code of two letters Eg : AA, AG, AC Triplet Code : Code of three letters Eg : AAC, AAU Non-sense codon : Codon which act as stop to synthesize amino acid. Initiating Codon: To initiate for the synthesis of amino acids Eg : AUG Characteristics of Genetic Code  Triplet nature  No overlapping  No punctuation  Universality  Degeneracy  Non-sense codon  Initiation codon  Co linearity MUTATION “Sudden changes that takes place in the genetic make up are known as mutation. Types of Mutation: Substitution Here one base is replaced by another base Frame shift mutation When the mutation involves loss or addition of a single base or a segment of DNA, then the entire reading frame will change the site of mutation. STRUCTURE OF t- RNA  Transfer of RNA is also known as soluble RNA (SRNA)  The tRNA is a small molecule compared with other molecule.  The tRNA is a clover leaf structure and it was suggested by R.W.Holley in strand.  These are three fold in clover leaf model with four loop and amino acid acceptor arm.  The acceptor arm carries an amino acid.  The anticodon loop has three anti codon nucleotides as extra arm called variable arm or Extra arm.  The amino acid acceptor and the anticodon arms are oriented in opposite directions. REGULATION OF GENE EXPRESSION Gene expression refers the genetic information stored in DNA or gene is expressed through the process of protein synthesis. LAC OPERA\ON CONCEPT  It was studied by F.Jacob & J.Monod in 1961. O = Operator gene P = Promoter gene R = Regulator gene Diagram showing the Lac operon model  When sugar lactose is added to the culture of E.Coli.  It induces the formation of three enzymes needed to breakdown lactose into glucose and galactose.  These enzymes are ß-galactocidase, permease and transacetylase  The genes for these enzymes are Lac Z, Lac Y, Lac A occur adjacent to each other are known as structural genes.  These three genes are operated by a single gene called operator  Another gene called regulator gene and it produces a protein called repressor.  This repressor binds with the operator and turns off the operon.  When there is an inducer it binds with repressor that pulls by operator to turn operon. HUMAN GENOME PROJECT <HGP> It is the project to understand the genetic composition and genetic instruction that make up a human. Goals of HGP (i) (ii) (iii) (iv) (v) To identify maximum number of genes in human DNA <20,000 to 25,000> To determine the chemical base pairs To store the information in data base Improve tools for data analysis To transfer related technologies to other sectors such as industries. SALIENT FEATURES OF HUMAN GENOME (i) (ii) (iii) (iv) (v) (vi) (i) (ii) Human genome contains 3164.7 million nucleotide bases. Average gene consists of 3,000 bases Total no. of genes are estimated as 30,000 Less than 2 percentages of the genome codes for protein. Repeated sequences make up very large portion of the Human genome. 1.4 million Locations have single base DNA differences. APPLICATIONS OF HGP Gene carries the information for the synthesis of various proteins. These proteins take different profiles such as enzymes, hormones and antigens. (iii) (iv) It will be the turning point and break through the in biology and medicine. HGP may be serve as a tool to eugenically concept. (v) It helps in gene therapy and diagnosis of defective genes. DNA FINGER PRINTING DNA finger printing was initially developed by Alec Jeffrey. Process of DNA finger Printing  DNA is extracted from the nuclei of whatever evidence is available. o Eg. From wise in case of blood sample. o From hair follicle cells that cling to the roots of hair that have fallen. o From spermatozoa’s in semen sample.  DNA sample is digested by a restriction enzyme which cuts the DNA in to fragments at specific sites.  These fragments are separated by gel – electrophoresis.  The above process is repeated by several enzymes; each one cutting at different sites and enough information is gathered to construct a detailed genetic finger printing of a person.  For detecting the fragments; there are special techniques which use radio active labeled DNA.  The final out come produces a picture of a strip of 30-40 dark bands which looks something like the bar codes used to identify other characters.  The degree of variation is so high that every individual with the exception of identical twins produces a unique band pattern, as every individual has a unique set of ordinary finger printing. Application  Application in forensic science.  Determining population and genetic diversities.  To solve the paternal disputes. Methods used in DNA finger Printing  VNTR o Variable number of Random Repeats o Southern Blot Hybridization method. REVIEW  Nucleic Acids are long polymers of nucleotides.  DNA stores genetic information  RNA helps in transfer and expression of information.  The double standard DNA helix has base pairing rule.  DNA replicates semi conservatively.  Transcription and translation brings genetic code.  Regulation of transcription is the primary step fro regulation of gene expression.  Human genome project was a mega-project that aimed to sequence every base in human genome.  DNA finger printing is a technique to find out variations in individuals of a population at DNA level.  It has immense application in the field of forensic science, genetic biodiversity and evolutionary biology. TERMINOLOGY  Base Pairing Rule  Codon  Euchromatin  Mutation  Hetrochromatin  Frame-shift mutation  Replication fork  Inducer  DNA ligase  Repressor  Exon  Operon  Intron ABBREVATIONS:  DNA – De oxy ribonucleic Acid  RNA Ribonucleic Acid  MRNA – Messenger Ribonucleic Acid  TRNA – Transfer  RRNA – Robesonia  UTR – Un translated Region.  AUG – Initiation codon  HGP – Human Genome Project.  ESTs – Expressed sequence Tags  BAC – Bacterial Artificial chromosome.  YAC – Yeast Artificial chromosome  SNPs – Single Nucleotide polymorphisms  VNTR – Variable number of Tandem Repeats QUESTIONNAIRE One Mark Each 1. How do DNA fragment get separated? 2. What do the triplets AUG and UGA respectively code for transcription and translation? 3. What conclusion is drawn from the blender experiment performed by Hershey and chase? 4. What is euchromatin? 5. How does the flow of information takes in viruses as reverse direction? Two Marks each 6. Differentiate between DNA and RNA. 7. What is mutation? Write the difference between deletion and frame shift mutation? 8. What is replication fork? Name the enzyme responsible for it? 9. What is codon? Name the various Non-sense codon and write its functions. 10.Write any four advantages of HGP. Three marks each 10. 11. 12. 13. 14. Briefly explain the Frederick Griffth experiment an DNA is a genetic material. Draw the structure of a tRNA and explain it. Write the various steps an DNA finger printing. How will you differentiate repetitive DNA and satellite DNA. Explain the Semi-conservative method of NA replication. Briefly explain the process of transcription in bacteria. Five marks each 15. Explain the Lac operon model of gene expression. 16. “DNA being more stable is preferred for storage of genetic material. For the translation of genetic information, RNA is better” Justify this statement. Chapter 7 EVOLUTION CONCEPT MAP ORIGIN OF LIFE EVOLUTION OF LIFE FORMS EVIDENCES OF EVOLUTION DIVERGENT EVOLUTION MECHANISM OF EVOLUTION HARDY WEINBERG LAW ORIGIN OF EVOLUTION OF MAN ADAPTIVE RADIATION CONVERGENT EVOLUTION BIOLOGICAL EVOLUTION FORE VIEW Evolution may be briefly defined as "descent with modification" - Charles Darwin. Modification occurs by interaction of genes and environment. The term evolution literally means unroll or unfold. It refers to a change from one form to another. Change in elements with time is called inorganic evolution. Change in leaving organisms with time is called organic or biological evolution. Organic evolution has produced a variety of organisms. The doctrine or theory of organic evolution states that the present complex organisms have evolved by gradual change in the earlier simpler forms of life over the ages. All organisms on earth have similar living materials, genetic code, life processes, the same principles of heredity and evolution. These similarities prove that all organisms evolved from a common primitive ancestor. Evolutionary biology is the study of history of life forms on earth. EXPOSITION OF THE CONCEPTS  Origin of life  Evolution of life forms - a theory  Evidences for evolution  Adaptive radiation  Biological evolution  Mechanism of evolution  Hardy Weinberg principle  Brief account of evolution  Origin and evolution of man  Review CONCEPTS  Our universe is almost 20 billion years old. Huge clusters of galaxies comprise the universe. Galaxies contain stars, clouds of gas and dust.  Big-bang theory explains the origin of universe. The theory states that the universe came into existence 15 billion years ago by a big-bang i.e., a thermo nuclear explosion. The universe expanded and hence the temperature came down. Hydrogen and helium formed later. The gases condensed under gravitation and formed the galaxies of the universe. In the solar system of the Milky Way galaxy, earth formed about 4.5 billion years ago. Water vapor, methane, carbon-di-oxide and ammonia released from the molten mass covered the surface. The UV rays from the sun broke up water into hydrogen and oxygen. As it cooled water vapor fell as rain. Ozone layer formed, life appeared 4 billion years back.  Spores formation theory (Panspermia) – Early Greek thinkers thought units of life called “spores” were transferred to different planets including earth.  Louis Pasteur – proved that life comes only from pre-existing life and disproved the theory of Spontaneous generation of life.  Oparin of Russia and Haldane of England proposed that the first form of life came from pre-existing non-living organic molecules like RNA, protein, etc.  Chemical Evolution – formation diverse organic molecules from inorganic constituents.  S.L.Miller Experiment – In 1953 Miller the American scientist created electric discharge in a closed flask with CH4, H2, NH3 and water vapor at 800 C. He observed formation of amino acids. Evolution of life forms - A Theory.  Theory of special creation by religious literature has three conditions. 1. All living organisms today where created as such. 2. Diversity was the same since creation and will be same in the future also. 3. The earth is about 4 thousand years old.  Charles Darwin, during a see voyage in a sail ship HMS Beagle around the world proved, living forms shears similarities to varying degrees even with living things existed millions of years ago.  New forms of life arose at different periods of history of earth.  Some survive better in natural conditions than others is called ‘fitness’ of the individual i.e. reproductive fitness according to Darwin.  Those fit better in an environment leave more progeny and will survive more and are ‘selected by nature’.  Alfred Wallace the naturalist, worked in Malay Archipelago also came to similar conclusion. Evidences for evolution  Fossils – Hard parts of life forms found in rocks which form sediments. Some of them appear similar to modern organisms. Eg. Dinosaurs, crocodile and birds.  Pale ontological evidence – life forms varied over time and certain life forms are restricted to certain geological time spans. New forms of life arisen at different times prove Pale ontological evidence.  Comparative anatomy and morphology – shows similarities and differences among organisms of today and of the past. Similarities shows common ancestors where shared. Eg: whales, bats, cheetah and human – all mammals share similarities in bone patterns of forelimbs, though these forelimbs perform different functions.  Divergent evolution – homology – same structure developed along different directions due to adaptations of different needs is called divergent evolution and these structures are homologous, in plants the thorn of Bougainvillea and tendrils of Cucurbita represent homology.  Convergent evolution – analogy – wings of birds and butterfly look alike but are not anatomically similar though they do similar function so analogous structures are the result of convergent evolution. Eg: Eye of the Octopus and of mammals, flippers of Penguins and Dolphins. In plants sweet potato (root modification) and potato (stem modification).  Bio-chemical similarities – similarities in proteins and give clues to common ancestry, shared ancestry. Adaptive radiation  Different species in a given geographical area starting from a point and laterally radiating to other areas of geographical habitats is called adaptive radiation. 1. Darwin’s finches – small black birds of many verities found in Galapagos Islands. 2. Another example is Australian marsupials. 3. Placental mammals in Austria show adaptive radiation. Biological evolution  Evolution by natural selection has started when cellular forms of life with difference in metabolic capability originated on earth. The rate of appearance of new forms is linked to the life cycle or the life span. Eg: Microbes multiply to million within hours by a chance in medium a part of them will survive.  This variant population outgrows the others and appears as a new species within days. The same thing to happen in higher organisms take millions of years as life span is in years. Natural selects for fitness. There is genetic basic for getting selected to evolve.  Adaptive ability is inherited. It has a genetic basic fitness is the end result of adaptive and natural selection. Branching descent and natural selection are the two key concepts of drawing theory of evolution.  Lamark, French naturalist said evolution occurred by use and disuse of organs. Eg: giraffes had to adapt by elongation of their necks – acquired character. Mechanism of evolution  Mendel’s inheritable “factors” influences phenol type Hugo De Varies work on evening prim rose brought the idea of mutations.  Large and sudden difference in a population causes evolution.  Mutations are random and directionless, while Darwinian variations are small and directional.  Evolution for Darwin was gradual while de varies mutation caused speciation and hence called saltation. Hardy Weinberg principle  In a given population, we can find the frequency of occurrence of alleles of a gene or a locus. The frequency remains fixed and remains the same through generations.  Hardy – Weinberg principle says that allele frequencies in a population are stable and constant from generation to generation. The gene pool i.e. total genes and their alleles in a population remains constant is called genetic equilibrium.  Sum total of all the allelic frequencies is one. Five factors affect Hardy – Weinberg equilibrium is genetic recombination and natural selection.  Some times the change in allele frequencies is so different in the new sample of population that they become a different species.  Founder effect: The original drafted population becomes founders and the effect is called ‘founder effect’. Brief account of evolution About 2000 million years ago (mya) the first cellular forms of life appeared on earth. Origin and evolution of man  About 15 mya, Hairy primates called Dryopithecus (ape like) and Ramapithecus (man like) were existing; they walked like gorillas and chimpanzees.  Australopithecines lived in east African grass lands hunted with stone weapons and ate fruits. These first humans like being the hominid were called Homo habilis with 650-800cc brain.  Fossils discovered in Java in 1891 revealed the next stage, i.e., Homo erectus with large brain of 900cc about 1.5 mya.  Neanderthal man with brain size 1400cc lived near east and central Asia between 100,000 – 40,000 years back.  Homo sapiens arose in Africa and moved across continents and developed distinct races during ice age between 75000 – 10000 years ago modern Homo sapiens arose. Industrial melanism. Review: (One mark each) 1. Name the first scientist to object ‘theory of a biogenesis’? 2. Name the scientist who disproved the theory of spontaneous generation of life? 3. Name the sources of energy in most accepted theory of origin of life? 4. What does the theory of special creation state? 5. What was sealed in the spark chamber in Miller and Urey experiment? 6. What was sealed in the spark chamber in Miller and Urey experiment. 7. Give the three key factors of modern concept of evolution. 8. How do genes mutate? 9. Give three mechanisms by which variant genotypes can be produced in nature? 10. Name the common ancestor of old world monkeys, apes and humans? (Two marks each) 11. Name A living fossil a. A missing link b. A connecting link c. Lamark’s theory of evolution 12. Name the common ancestor of great apes and man? 13. Name the earliest fossil of prehistoric man. 14. Name the most primitive apes. 15. Write the cranial capacity of man. 16. Name the extinct representative of modern man. 17. Name the primitive family of man 18. How did the original reducing atmosphere of primitive earth change? 19. Explain the term Bio-genesis. 20. Explain the importance of Miller and Urey experiment. 21. Explain the existence of analogous organs. 22. What are Darwin’s finches, what is its importance. 23. Archaeopteryx is considered as the connecting link between reptiles and birds. Prove. 24. What is molecular biology? 25. Name the variation which forms the raw material for organic evolution? 26. Name the animal regarded as man’s nearest relative. 27. List the conditions found on the primitive earth? 28. What is Exobiology? 29. How was the ozone layer formed? 30. State the Oparin and Haldane hypothesis about the primeval conditions of the earth. (Three marks each) 31. State the major theories of origin of life. 32. What is paleontology? 33. How are the fossils formed? 34. What are homologous organs? Explain with examples. 35. What are analogous organs. Explain with examples? 36. What is meant by “Pangaea”? 37. What do you mean by (a) connecting link? (b) missing link? 38. List Lamark’s factors for the theory of biological evolution? 39. Write the main postulates of Darwin theory of Natural selection? (Five marks each) 40. Explain how do new species arise according to De Veris mutation theory of organic evolution? 41. How was Darwin’s theory of Natural selection proved by Leader berg? 42. What are the drawbacks of Darwin’s Species”? 43. Write a note on – Industrial melanism? 44. What roles have cell and molecular biology play in solving problems of human ancestry? *********** UNIT – 8 Chapter 8 HUMAN HEALTH AND DISEASES CONCEPT MAP Bacterial Viral diseases diseases Innate immunity Acquired immunity Human Health and Diseases Protozoan Cancer diseases Drugs , Alcohol abuse Dr.M.S.Swaminathan FORE VIEW: Criteria for health.  Factors affecting health.  Common diseases in man and pathogen causing diseases.  Typhoid – widal test.  Pneumonia.  common cold.  Malaria- Life cycle of Plasmodium vivax.  Amoebiasis.  Ascariasis  Elephantiasis/ Filariasis.  Ring Worms. IMMUNITY:Types of immunity Innate immunity.  Acquired immunity-auto immunity.-  Active immunity.  Passive immunity.  Lymphoid Organs AIDS  Causative organism.  Replication of retro virus.  Mode of transmission.  Prevention of AIDS. CANCER: Types and causes of cancer.  Detection and diagnosis. DRUG AND ALCOHOL ABUSE:Types of drugs Opioids.  Cannabinoids.  Cocaine/Coke Effects of drugs and alcohol abuse Prevention and control. EXPOSITION OF THE CONCEPTS Health- Physical, mental and social well being. Factors affecting health Genetic disorders-inheritance of genetic disorders from parents from birth.  Infections.  Food and water. Factors promoting health Clean food and water.  Exercise and rest. Types of diseasesInfectious disease - Transmitted from one person to another. Ex., common cold. Non-infectious diseases-Not transmitted from one person to another. Excancer. Common human diseases Bacterial diseases viral diseases Typhoid pneumonia common cold protozoan diseases malaria amoebiasis elephantiasis diseases Fungal diseases ascariasis Ring worm Bacterial diseases Factors Causative organism Typhoid Salmonella typhi Mode of transmission Through contaminated food and water Organs affected Symptoms Small intestine and other organs High fever 3940°c,weakness,stomach pain, constipation, head ache and loss of appetite Personal hygiene, public hygiene Preventive measures pneumonia streptococcus pneumoniae and haemophilous influenzae sharing glasses and utensils, inhalation of the droplets/aerosols released by an infected person. Alveoli of lungs Fever, chills, cough and head ache lips and finger nails turn gray to bluish in colour. personal hygiene, public hygiene, vaccination Viral diseases Causative organism Mode of transmission Common cold Rhino virus Droplets from cough and sneezes of infected persons. Contaminated pens, books, cups etc. Organs affected Symptoms Nose and respiratory passage Nasal congestion, nasal discharge, sore throat, hoarseness, cough, head - ache, tiredness Preventive measures personal hygiene, public hygiene, vaccination Protozoan diseases FACTORS Malaria Ameobiasis Elephantiasis Ascariasis Causative organism Mode of trans mission Plasmodiu m vivax Mosquito bite Entameoba histolytica Contaminated food and water Wuchereria Ascaris Female mosquito bite Organs affected Symptoms Liver and RBCs Chill and high fever recurring every 3-4 days Large intestine Legs, arm, lymphatic glands Inflammation of legs, arms, lymphatic glands and genital organs Contamina ted water, vegetables , fruits Intestine Preventive measures Vectors Personal and and public hygiene breeding places must be controlled and eliminated, use of mosquito nets, use of fish Gambusia in ponds ,insecticid es Constipation, abdominal pain and cramps, stools with excess mucous and blood clots Vectors and breeding places must be controlled and eliminated, use of mosquito nets, use of fish Gambusia in ponds ,insecticides Internal breeding, muscular pain, fever, anemia and blockage of the intestinal passage Personal and public hygiene Fungal diseases FACTORS Causative organism Mode of transmission Organs affected Symptoms Preventive measures Ring worm diseases Microsporum, Trichophyton, Epidermophyton From soil, using towels, clothes and comb of infected individuals Skin ,nails, scalp Dry scaly lesions on skin, nails and scalp ,intense itching Personal and public hygiene Life Cycle of Plasmodium Sporozoites of plasmodium vivax Sporozoites multiply and get stored in salivary glands Mosquito bite Human livercells Female Anopheles mosquito from infected person when it bites. for further development (Multiplication of parasite RBCs Chill and high fever every 3-4 days Rupturing of RBCs Release haemozoin(toxin) IMMUNITY Ability of an organism to fight the disease causing organisms Types : (i) Innate immunity (ii) Acquired immunity (iii) Active immunity –Auto immunity (iv) Passive immunity INNATE IMMUNITY (i) Non specific – not pathogen specific . (ii) Immune response - by barriers. FOUR TYPES OF BARRIERS : (a) Physical barriers-eg. Skin , mucous coating of the epithelium lining the respiratory , gastrointestinal & uro-genital tracts ,prevents microbial entry. (b) Physiological barriersacid in stomach,saliva in mouth . (c) Cellular barriers-leucocytes like polymorphonuclear leucocytes(PMNL),neutrophi ls,monocytes & natural killer (type of lymphocytes) in blood & macrophages ( in tissues). (d) Cytokine barriers : virus infected cells – interferons – protect non infected cells . ACQUIRED IMMUITY (i)Pathogen specific. (ii)Immune responses –primary &secondary responses (anamnestic) by’ B ‘&’ T ‘ lymphocytes. B lymphocytes- produce antibodies (proteins).T lymphocytes help B cells to produce it .T cells involve in cell-mediated immunity essential for the body to differentiate self and non self tissues ,. 1.Exposure to some infectious agents results in diseases . Why? 2.Why is it that the organs cannot be taken from just anybody? 3.What is it that the doctors check in them? Structure of an Antibody molecule 2 small light chains 1.Four peptide chains 2 longer heavy chains ie.H2L2 2.Peptide chains have antigen binding site GRAFTING Technique by which transplantation of human organs such as heart, eye, liver, kidney - for normal functioning.  Depend on tissue matching and blood group matching  Cell mediated immune response is responsible for graft rejection. if the tissues and blood groups of donor are not matched with the recipient’s tissuesgrafting rejected. ACTIVE IMMUNITY (i)An organism produces Antibodies on its own (proteins)when antigen enters in it . (ii) Slow process and takes long time to produce anti bodies. Eg. DPT vaccine. PASSIVE IMMUNITY (i)Ready made antibodies are given to protect the body against foreign antigen. (ii)Rapid process and takes short time for response. Eg. (a) Colostrums present in mother’s milk has antibodies Ig A to protect the infant. (b) Antibodies received by foetus from mother through their placenta. VACCINATION: Inactivated / weakened pathogen or antigenic proteins of pathogen are introduced into the body.  They produce antibodies against these antigens and neutralize them in the body.  Vaccines produce 'B' & 'T' cells – recognize the pathogen and produce more antibodies- kill the pathogen. PASSIVE IMMUNISATION:  Provides quick immune response at the time of infection by deadly microbes  Eg. Injection of preformed Anti bodies - tetanus.& snake bite. ALLERGY: Response of the immune system to certain antigens such as Mites, dust, pollens , animal dander etc. (allergens) Mast cells of our body produce histamine and serotonin allergy. Symptom: sneezing, watery eyes, running nose, difficulty in breathing . Antibodies produced: Ig E type. When you go to a new place you start sneezing , wheezing and when you come away your symptoms disappeared why? How to determine the cause of allergy?  Patients are exposed to or infected with small doses of possible allergens  The reactions are studied . REMEDY:Drugs like anti - histamine , adrenaline and steroids (for quick relief) AUTO IMMUNITY :  Body can attack self cells due to genetic and other unknown reasons – results in auto immune disease (destruction of its own cells) Ex. Rheumatoid arthritis . IMMUNE SYSTEM Lymphoid organs- Lymphatic tissues (Where origin, Antibodies located within the Produced by maturation lining of the respiratory B&T lymphocytes and proliferation of digestive and urogenital tract- to fight with antigens. lymphocytes occur) Mucosal associated protein in nature. lymphoid tissues (MALT) Eg. Ig A IgM IgE IgG Primary lymphoid organs secondary lymphoid organs Eg. bone marrow, thymus spleen, lymph nodes, tonsils, Peyer’s patches of small intestine and appendix LYMPHOID ORGANS BONE MARROW THYMUS .(present inside the 1.Located near the bones) SPLEEN 1.Largest lymphatic gland LYMPHNODES 1.Small solid heart and beneath 2.contain lymphocytes structures located (lymphocytes are breast bone and phagocytes at diff. points produced) 2 reduces in size with 3.filter blood- borne T lymphocytes age and becomes Develop and mature very small at puberty 3. T lymphocytes develop and mature micro organisms in the tissue 4.large reservoir of erythrocytes. 2.trap the micro 0rganism or Other antigens 3. activates the lymphocyte & cause the immune 1.What are the different types of lymphoid organs? 2.Where do the T-lymphocytes develop and mature? 3.Where is thymus gland located? 4.Mention any two functions of spleen. 5.Mention the significance of lymph nodes. AIDS:-Acquired Immuno Deficiency Syndrome It is not a congenital disease but acquired one. Causative Organism: Human Immuno Deficiency Virus . Retro virus enclosing the RNA genome. Mode of transmission 1.Sexual contact with infected person. 2.By transfusion of contaminated blood and blood products. 3. By sharing infected needles. 4.Infected mother to child through placenta. 5.Individuals who have multiple sexual partners. 6.Drug addicts who take drugs intravenously. Formation of virus inside the body(refer fig 8.6-page155 NCERT TEXT) HIV virus-------> macrophages of the body ------->RNA genome of the virus replicates---->reverse transcriptase viral DNA---->incorporates into host cell DNA---->infected cells produce viral particles ----->enter----->'T' helper lymphocytes replicates ---->viral progeny ----->attack other helper 'T' lymphocytes in blood.------->decrease in the no. of T helper cells------->person becomes immuno deficient. Symptoms: Fever, diarrhoea, weight loss. Immuno deficiency. Confirmatory Test: ELISA PREVENTIVE MEASURES: 1.Safe blood 2.Use of disposable needles and syringes. 3.Free distribution of condoms. 4.Control of drug abuse. 5.regular check-ups for HIV CANCER:-Uncontrolled division and growth of cell gives rise to masses of cells called tumor. --cancerous cells do not show contact inhibition (i.e, when a cell contact other cell it stops its growth) whereas cancerous cells continue to divide giving rise to masses of cells which leads to tumor formation. TYPES OF TUMOR Benign tumor 1.Confined to their Malignant tumor 1.Proliferate to form a mass of original location . 2. Do not spread to cells-neoplasts or tumor cells. 2.Divide rapidly , and cells detached other parts. from tumor spread to distant parts 3.cause little damage. through blood and produced new eg:brain tumor tumor-metastasis 3. Cause great damage. Eg:blood cancer CAUSES OF CANCER:CARCINOGENS-Agents causing cancer. 1. Physical agents-ionizing radiations X-rays and gamma rays. .Non ionizing radiation uv causes DNA damage 2. 3. Chemical agents-tobacco smoke- nicotin Biological agents-oncogenic viruses-(cancer causing viruses) – activated cellular oncogenes or proto oncogenes(in normal cells) CANCER DETECTION AND CAUSES : Cancer detection- by  Biopsy and histopathological studies of the tissue and blood .  Biopsy: Suspected tissue cut into thin section-stainedexamine under microscope .  Bone marrow tests for leukemia.  Radiography technology-( Use of x-rays) .  Computed tomography – X-rays are used to make the 3-D images of the internal objects.  MRI (Magnetic resonance imaging ) magnetic field and nonionising radiations are used to find pathological and physiological changes .  Antibodies against antigens causing cancer .  Identification of Oncogenes with the help of molecular biology technology to prevent them from further exposure to Carcinogens .  Ex. Tobacco smoke in case of lung cancer . TREATMENT OF CANCER: 1. Surgery 2. Radiation therapy and immuno therapy-tumor cells alone are irradiated lethally. 3. Chemotherapeutic drugs (These drugs can cause side effects like hair loss, anemia etc.] 4. Immune system : Ex. Interferon activates immune system & helps in destroying tumor. 1. 2. 3. 4. 5. What is cancer? What are the types of tumor? Differentiate it. Define metastasis . Classify the causes of cancer. Briefly explain the methods by which cancer is deducted & diagnosed. 6. Enumerate the various approaches for the treatment of cancer. DRUGS & ALCOHOL ABUSE SOURCES: Flowers of some plants and Fungi. Drugs commonly used OPIOIDS COCA ALKALOIDS (i) Ex.& sources : Heroin (diacetyl morphine) CANNABINOIDS (i) Ex. and sources: ganja, hashish marijuana(leaves, flowers & resins -papaver somniferum. of cannabis sativa) (ii)Physical property: white, (ii) Modes of ingestion: Taken by odorless, bitter, crystalline inhalation and oral ingestion. compound. (iii) preparation - acetylation of morphine. (iii) Bind with cannabinoid receptors (iv) Modes of ingestion: taken by -brain affect cardio vascular system snorting & injection. (v) Ingestion action: Opioids bind to opioid receptors-present in our central nervous system & gastro intestinal tract. Heroin- a depressant- slows down body function. COCA ALKALOIDS:Otherwise Known as COCAINE – COKE /CRACK (i) Sources: Erythroxylum coca-Atropa belladonna, datura. (ii) Mode of ingestion: Taken by snorting. (iii) Action: it interferers with the transport of the neuro transmitter – dopamine. (iv) Stimulates central nervous system and produce a sense of euphoria (sense of well being) and increased energy.- hallucination DRUGS USED AS MEDICINES:  Barbiturates, amphetamines benzodiazepines , lysergic acid diethyl amides (LSD).  Used to cope with mental illness-depressions and insomnia.  Morphine-and painkiller. Harmful effects:  Chewing and smoking tobacco – Nicotine present in tobacco stimulates adrenal gland – releases adrenaline + nor adrenaline – blood stream – increases blood pressure – increase heart rate.  Tobacco chewing: Cancer of the oral cavity , cancer of lungs , urinary bladder & throat .  Smoking : Bronchitis , Emphysema , coronary heart disease , Gastric ulcer etc.  : Increases the content in blood & reduces the concentration Haem – bound Oxygen - Oxygen deficiency in the body . 1. Briefly mention the effects of drugs with example. Explain how chewing & smoking of tobacco effect our health. ADOLESCENCE AND DRUG / ALCOHOL ABUSE ADOLESCENCE : A period and a process during which a child becomes mature in terms of his / her activities and beliefs for effective participation in society.  It is a bridge linking childhood and adulthood .  It is the phase of mental and psychological development of will. ADOLESCENCE PERIOD: 12 – 18 yrs . CAUSES FOR INTAKE OF ALCOHOL:       Natural curiosity To escape from stress and pressure The perception among youth Television, movies, newspapers, internet. Unstable or unsupportive family structures. Peer pressure. DRUG ADDICTION: psychological – attachment to the drugs and dependent on their use.       To some effects – euphoria & a temporary feeling of well being. Repeated use of drugs increases the tolerance level of receptors present in our body . Thus receptors respond to higher doses of drugs / alcohol. That leads to greater intake & addiction. The addiction potential of drugs & alcohol makes the user to use it regularly. Thus the person gets addicted. WITHDRAWAL SYNDROME: SYMPTOMS CAUSED DUE TO SUDDEN DISCONTINUITY OF THE DRUGS / ALCOHOL ARE :     Anxiety Shakiness Nausea sweating 1. What is Adolescence? 2. What are the effects of alcohol consumption? 3. Define withdrawal syndrome. EFFECTS OF DRUGS: 1. Reckless behavior. 2. Vandalism and violence 3. Respiratory failure → coma and death 4. Heart failure - cerebral hemorrhage 5. Drop in academic performance 6. Unexplained absence from school / college 7. Lack of interest in personal hygiene 8. Withdrawal 9. Isolation 10. Depression , fatigue 11. Aggressive and rebellion behavior 12. Deteriorating relationships with family and friends. 13. Loss of interest in hobbies 14. Change in sleeping and eating habits 15. Fluctuations in weight, appetite etc. 16. Mental and financial distress. 17. 18. 19. Intravenous infection of drugs can cause AIDS and hepatitis B. Chronic usage damages nervous system and liver (cirrhosis) Intake during pregnancy can affect fetus in sports , PRECAUTION AND CONTROL: 1. Avoid undue peer pressure. 2. Education and counseling . 3. Seeking help from parents and peers. 4. Looking for danger signs. 5. Seeking professional and medical help. 1. What is adolescence period? 2. What are the factors associated with the usage of drugs? 3. How will you control or prevent drug abuse? REVIEW: TERMINOLOGY : 1. 2. 3. 4. 5. 6. 7. 8. Immunity:-Ability of the body to resist antigen. Congenital diseases:-diseases produced from birth itself. Humoral immune system:-Antibody mediated immune system. defend our body by producing antibodies that inactivate microbes. Cell mediated immune system:-defend our body by producing three types of T cells.killer Tcells-destroy the non self cells.helper T cellsstimulate B cells to produce antibodies.suppressor Tcells-inhibit immune system attaching own cells. colostrum:-immunoglobulin present in mother’s blood has antibodies(IgA) to protect the infant. Auto-immune:-Attack of body on its own cells.Ex Rheumatoid arthritis. Retro virus:-virus having RNAas the genetic material. Ex. HIV virus Metastasis:-movement of tumor cells from a place to the distant site through blood and develop a new tumor when they get lodged. 9. Oncogenes:- cancer causing genes. 10. Proto oncogenes:-Inactive oncogenes present in normal cells can cause cancer when activated. Interferons:- Proteinaceous substance that can activate immune system to destroy tumor. Cirrhosis- a chronic disease of the liver marked by the degenration of cells and the thickening of surrounding tissues. 11. 12. QUESTIONNAIRE: (2 marks) 1. Differentiate infectious and non-infectious diseases. 2. Name the diseases that can be confirmed by widal test and ELISA. 3. Distinguish innate and acquired immunity. 4. Why is mother’s milk essential for the new born infant? What is the antibody it contains? To which type of immunity it belongs? 5. Define allergy. Name the antibody produced against this in our body. 6. Why is rheumatoid arthritis considered an auto immune disease? (3 marks) 7. Write a causative organism, symptoms and remedial measures of typhoid, pneumonia and malaria. 8. Explain briefly life cycle of Plasmodium vivax. 9. Write a causative organism, symptoms and remedial measures of ascariasis, filiariasis and ring worms. (5 marks) 10. What are the primary and secondary lymphoid organs? Give any two example of each. What are the lymphoid organs provide micro environment for the development of ‘T’ lymphocytes. Write down any two significance of spleen? 11. Classify drugs with an example. Write down their effect. 12. Name two drugs that can be used as medicines with its role. 13. Write down any four withdrawal syndrome. 14. Briefly mention the effect of drugs in general. ----------------------------------------------------- Chapter 9 STRATEGIES FOR ENHANCEMENT IN FOOD PRODUCTION FORE VIEW Demand of food is met by agricultural practice of breeding and raising livestock such as buffaloes, cows, pigs, horses, cattle, sheep etc to produce milk, egg, meat, honey etc – Animal Husbandry and Plant Breeding. Animal Husbandry includes management of farm and farm animals through 1. 2. 3. 4. Poultry farming Dairy farming –Animals breeding Fisheries –Aquaculture and Pisciculture-Blue revolution Apiculture In breeding Out breeding Multiple ovulation embryo transfer technology Animal breeding Artificial insemination Inter specific hybridisation Out crossing Cross breeding Plant breeding- used to create varieties of resistance and high yield type through conventional and mutation breeding. It has been used to increase protein, vitamin, oil content etc. Techniques of tissues culture and somatic hybridization manipulation of plants in vitro to produce new varieties. Plant breeding Somatic hybridisati on Tissue culture EXPOSITION OF THE CONCEPTS ANIMAL HUSBANDARY: Agricultural practice of breeding and raising livestock such as buffaloes, cows, pigs, horses, cattle , sheep, camels and goats etc to products like milk , egg, meat wool , silk, honey etc. ANIMAL HUSBANDRY(Rearing of Livestock) POULTRY FARMING FISHERIES Rearing of chicken Rearing, catching and selling Ducks, turkey and geese for of fish, molluscs and Meat and egg purpose crustaceans(prawns, crabs) Dairy farm 1. Differentiate dairy farming & poultry management. Poultry farm BREEDS : A group of animals related by descent and similar in most characters. Eg. Jersey in cattle and leghorn in chickens. ANIMAL BREEDING IN BREEDING (i)Mating of closely related individuals with in the same breed for 4-6 Generations. (ii)Superior males & superior females of the same breed are mated in pairs (iii) progeny are evaluated and superior males & females (that produces more milk for lactation) are identified for further mating. OUT BREEDING (i) breeding of unrelated animals either the individual of the same breed (but having no common ancestors) or Between different breeds(cross breeding) or different species(interspecific hybridization) Significances of inbreeding: Increases homozygosity  Evolves cells of a pure line in any animal.  Explores harmful recessive genes to be eliminated by selection.  Accumulates superior genes & eliminates less desirable genes.  Selection increases the productivity of inbred population. Disadvantages:  Continuous inbreeding reduces fertility and productivityinbreeding depression. Remedy: selected animals should be mated with unrelated superior animals of the same breed to restore fertility & yield . OUT CROSSING CROSS BREEDING Mating animals of the same breed but having no common ancestors on either side of their pedigree upto 4 to 6 generations. Mating between superior male of one breed with superior females of another breed . Offspring- “ out cross” Progeny –>“hybrids” SIGNIFICANCE: SIGNIFICANCES:-  Increase milk production, growth rate in below average animals.  Helps to overcome inbreeding depressions.  Best method for the animals Show below average productivity.  Combines desirable qualities of two different breeds .  New stable breeds( superior) are developed by MAKING THE HYBRIDS TO UNDERGO breeding and selection of hybrids. Ex: Hisardale –new breed of sheep in Punjab INTERSPECIFIC HYBRIDISATION: Mating of male & female animals of two different species. Progeny- shows combination of desirable features of both the parents. Eg: mule produced by male donkey and female horse 1. Differentiate out crossing & cross breeding. 2. what are the terms you apply for the offspring produced by out crossing & crossbreeding? 3. What is interspecific hybridization.? Give example. 4. Do you know what cross leads to production of the mules.? The First Mule Cloned ARTIFICIAL INSEMINATION: The process by which the semen from selected male parent is injected into the reproductive tract of the selected female by the breeder. USES: 1. Desirable mating can be carried out.(is controlled breeding experiment) 2. Semen can be transported in frozen form to distant places. 3. Wastage of semen can be avoided. 4. Semen can be stored. 5.Helps to overcome the problem of normal mating. 1. What is artificial insemination? 2. Can you discuss & list some natural problems which can be overcome by artificial insemination? 3. Rate of crossing mature male and female animal fairly low even if artificial insemination is carried out. How can if be solved? 4. What is the other way of to improve chances of production of hybrids. Explain. MULTIPLE OVULATION EMBRYO TRANSFER TECHNOLOGY (MOET) 1. Cow administered with FSH hormones produces 6-8 eggs instead of one egg/cycle follicular maturation and super ovulation. 2. It is mated with a bull/artificially inseminated. 3. The fertilized eggs at 8 – 32 cells stage are transferred to surrogate mothers. 4. Results in high milk yielding breeds of females and high quality (lean meat with less lipid ) meat yielding bulls. Ex: high qualities of cattle, sheep , rabbits, buffaloes & mares. Advantages: 1. To improve chances of production of hybrids. 2. To increase milk yielding capacity and meat yielding capacity.(lean meat with lipid). APICULTURE: Maintenance of hives of honeybees for the production of honey. HONEY BEE Honey bee wax Food and medicine cosmetics and polishes  The most common species is Apis indica BEE – KEEPING: 1) Knowledge of the nature and habits of bees. 2) Selection of suitable location for keeping the beehives. 3) Catching and hiving of swarms ( group of bees) 4) Management of beehives during different seasons. 5) Handling & collection of honey & beeswax. USES: 1. Bees – pollinators ex: brassica, apple & pear. 2. Beehives in crop fields increases pollination, efficiency, & improves the yield. 1) 2) 3) 4) Define apiculture. What are the points kept in view for successful bee keeping? Name the common species of honey bee? Used for rearing Mention any two uses of bee- keeping. FISHERIES : Catching, processing or selling of fish, shellfish or other aquatic animals. EDIBLE FRESH WATER FISH : Catla, rohu . & common carp. MARINE WATER FISH: Hilsa, Sardines, mackerel and pomfrets PISCICULTURE Culture of fish AQUACULTURE Culture of aquatic plants and animals such as prawn, crab, lobster, edible oyster Etc. BLUE REVOLUTION Increasing production of aquatic animals for food & other purpose GREEN REVOLUTION Increasing production of wheat varieties. Questions: 1. Differentiate pisciculture & aquaculture. 2. define blue revolution. 3. Give two examples of each marine and fresh water fish. PLANT BREEDING Manipulation of plant species to create desired plant types of better yield and disease resistance. CHARACTERS INCORPORATED INTO CROP PLANTS BY BREEDERS 1. Increased crop yield 2. Improved quality 3. Increased tolerance to environmental stresses such as a) Salinity b) Extreme temperature c) Drought 4. Resistance to pathogens (viruses, fungi, bacteria) 5. Increase tolerance to insect pests STEPS INVOLVED IN PLANT BREEDING 1. Collection of variability Collection and preservation of different varieties which have genetic variability, species and relatives of cultivated species (example: germplasm collection of plants having all the diverse alleles for all genes in a given crop) 2. Evaluation and selection of parents Plants with desirable combination of characters are identified and multiplied and used in the process of hybridization. Example: creation of pure lines 3. Cross hybridization among the selected parents Desired characters from the two different parents are combined by cross hybridizing the two parents(high protein quality of one parent combine with disease resistant variety of another parent) ↓ Hybrids that combine the desired characters in one plant are produced. DISADVANTAGES: 1. Time consuming processes 2. The hybrids may or may not combine the desired characters. 4. Selection and testing of superior recombinants:   Plants that have combination of desired character are selected (i.e) plants that are supported to both the parents . These are self pollinated for many generations till they reach homozygosity. 5. Testing , release and commercialization of new cultivars :    Yields and disease resistance of newly selected lines are evaluated under crop management practices. The materials are tested in farmer’s fields for three growing seasons at several agroclimatic zones in the country. Yield and other characters are compared with a reference cultivar 1. Crops show high yield will be selected - disease resistant. Ex. Semi dwarf varieties of wheat and rice ( high yielding types) – sonalika and kalyan sona ( wheat). 2. IR 8 ,Taichung Native-1 (Taiwan dwarf varieties of rice) Jaya and ratna (Indian semi-dwarf varieties of rice) 3. Sugar cane: Saccharum barrberi ( poor sugar content and yield grown in North India) crossed with saccharum officinarum (thick stem with high sugar content grows in South India ) to get a variety which is of high yield , thick stem , high sugar and ability to grow in North India. 4 MILLETS : (Hybrid maize, jowar and bajra ) Advantage of Hybrid breeding 1. Develop high yielding varieties resistant to water stress. PLANT BREEDING FOR DISEASE RESISTANCE :  Disease resistance cultivars enhance food production.  Reduce the dependence on fungicides and bactericides. CRITERIA REQUIRED: 1. Knowledge on causative organism . 2. Mode of transmission: Ex. (i) Fungi- rust of wheat, red rot of sugar cane, late blight of potato. (ii) Bacteria – black rot of crucifers. (iii) Viruses- tobacco mosaic, turnip mosaic etc. METHODS OF BREEDING FOR DISEASE RESISTANCE Conventional method : breeding Hybridisation Selection 2.Mutation STEPS: 1.Screening germplasm for resistance resources. 2. Hybridisation of related parents. 3. Selection and evaluation of the hybrids. 4. Testing and release of new varieties. Crop varieties bred by hybridization and selection for Disease resistance to fungi, bacteria and viral diseases MUTATION BREEDING: 1. INDUCTION OF MUTATION  Chemical or radiations in plants to develop desirable characters .  These plants are selected and used as a source in breeding 2.Introduction of genes.  Transfer of resistant gene by sexual hybridization between the target &the source of the plant .  Introduction of resistant genes from wild relatives into the high yielding varieties. Gene for resistance to yellow mosaic virus introduced in bhindi Abelmoschus esculentus from wild species - A. esculentus parbhani kranti ( a new verities) 1. What are the methods by which plant breeding for disease resistance can be done? 2. Mention any two examples for mutation breeding. 3. Name the crop variety of wheat resistant to leaf rust and hill bunt. 4. Name the crop variety of cowpea resistance to bacterial blight. Plant breeding for developing insect/pest resistant varieties:Morphological, physiological and biochemical characteristics are responsible for insect resistance in host crop plants. Morphological characters Eg: hairy leaves of plants – resistance to pest. resistance to Jassids----------->cotton resistance to cereal leaf beetle---------->wheat Solid stems in wheat -------------> resistance to beetle sawfly Smooth leaved and nectarless cotton ---------- resistance to bollworms as they do not attract bollworms. Biochemical characteristic:  High aspartic acid  Low N2  Low sugar content in maize CROP VARITIES FOR INSECT } } → resistant to stem borers } PEST RESISTANCE: 1. Mention some morphological characteristics of wheat and cotton responsible for resistance to pests give examples. 2. What are the biochemical characteristics that make maize resistant against stem borers? PLANT BREEDING FOR IMPROVED FOOD QUALITY Diet lacking Micronutrients – iron Vitamin A Iodine Zinc 1. Increase risk for diseases 2. Reduces life span 3. Reduces mental abilities in human BIOFORTIFICATION Breeding crops with higher levels of vitamins and minerals for higher proteins and healthier fats. OBJECTIVE: 1. 2. 3. 4. 5. To improve public health Protein content and quality Oil content and quality Vitamin content Micronutrient and mineral content Example 1. MAIZE HYBRIDS : twice the amount of amino acids , lysine and tryptophan 2. WHEAT VARIETY: Atlas 66-High protein content . 3. Vitamin A enriched carrots , spinach ,pumpkin 4. Vitamin C enriched bitter gourd mustard,bathua, tomato. 5. Calcium enriched – spinach, bathua 6. Protein enriched beans - broad lab lab, French and garden peas. 1. Define biofortification. 2. What are the objectives of plant breeding for biofortification. 3. Mention few eg. Of plants produced by biofortification. SINGLE CELL PROTEIN : Microbes grown on industrial scale as a source of protein for animals and human nutrition –single cell protein. MICROBES AS FOOD Example: Spirulina rich in protein , minerals, fats, carbohydrates and vitamins. MUSHROOM - rich in proteins MATERIALS NEEDED FOR GROWTH OF SPIRULINA 1. 2. 3. 4. 5. Waste water from potato processing plants (containing starch) Straw Molasses Animal manure Sewage Q1. what is single cell protein? Q2. what are the materials needed for growing spirulina? Q3. mention few examples of microbes that act as food for humans. TISSUE CULTURE: Regeneration of whole plants from explants ( any part of a plant grown in a test tube) under sterile conditions in special nutrient media TOTIPOTENCY: The capacity to generate a whole plant from any cell / explant. Components of nutrient medium      for tissue culture: Carbon source-sucrose Inorganic salts Vitamins Amino acids Growth regulators like auxins and cytokinins etc. APPLICATION OF TISSUE CULTURE: 1. Micro propagation: Propagation of large no. of plants in very short durations through tissue culture. SOMACLONES :Plants produced by a tissue culture method are identical to the original plant . PLANTS PRODUCED BY THIS (SOMACLONE) METHOD : Somaclones of tomato, banana, apple etc. 2. Recovery of healthy plants from diseased plants by growing the meristem ( virus free) of infected plants in vitro to obtain virus free plants. Ex. Meristems of banana, sugarcane, potato etc. 3. Somatic hybridization: Hybrid Protoplasts plant cell after digesting the cell wall). ie cell cytoblasm surrounded by plasma membrane alone – fusion of protoplasts of plant cells having desirable characters. Ex., Fusion of protoplasts of potato and tomato – pomato. 1. Define tissue culture. 2. What are the components required to make nutrient medium used in tissue culture? 3. Mention few applications of tissue culture? REVIEW Breed: A group of animals related by descent and similar in characters like general appearance, features, sizes, configuration etc. 1. Surrogate mother: A female who grows someone else’s zygote/embryo in her own uterus for full gestation period and delivers the baby. 2. Aquaculture: Cultivation or rearing of aquatic plants and animals. 3. Pisciculture: Rearing of fish. Norman E.Borlaug- developed semi dwarf varieties of wheat international centre for wheat and maize. IARI: Indian agricultural research institute New Delhi(several vegetation crops rich in vitamins and minerals). 4. Cultivar: Plant variety produced by cultivation. 5. Breed: A group of animals related by descent and similar in characters like general appearance, features, sizes, configuration etc. Questionnaire 2 marks 1. What is animal husbandry? Give example. Name some products obtained from it. 2. List out the measures taken in dairy farm to maintain animals. 3. What are the purposes for which dairy management is done? 4. What is poultry farm management? What are its important components ? 5. Differentiate in breeding from out breeding. 6. What is breed? Give one example of breed in cattle and chicken. 3 marks1. Mention any significances of in breeding. 2. What is the disadvantage of in breeding? How will you rectify it? 3. Differentiate out crossing and cross breeding. Write down any one significance of each. 5 Marks1. Expand MOET Briefly explain the method.What are the advantages of this method? 2. Enumerate the points for successful bee-keeping. 3. List out the characters importance into crop plants by breeders. 4. Explain the steps involved in plant breeding. 5. List out hybrid varieties of wheat, rice, and sugar cane. Write down the advantage of hybrid breeding. 6. What are the two methods adapted for plant breeding for disease resistance? explain it. 7. List out any five crop varieties breed by hydbridisation and selection and the disease to which they are resistant. Chapter 10 MICROBES IN HUMAN WELFARE CONCEPT MAP Industrial products House hold products Biofertilisers Sewage treatment Biogas production MICROBES IN HUMAN WELFARE Biocontrol agents FOREVIEW  MICROBES IN HOUSE HOLD PRODUCTS—curd & dough used for baking and preparing idlis dosas made soft.  MICROBES IN INDUSTRIAL PRODUCTS—alcoholic beverages,antibiotics, chemicals ,enzymes and bioactive molecules.  MICROBES IN SEWAGE TREATMENT –aerobic & anaerobic bacteria (methanobacteria)  MICROBES IN PRODUCTIOn OF BIO – GAS-- methanobacteria  MICROBES AS BIO CONTROL AGENTS- Bacillus thuringiensis  MICROBES AS BIO FERTILISERS- Rhizobium, Mycorrhizae EXPOSITION OF THE CONCEPTS MICROBES IN HOUSE HOLD PRODUCTS : I . Lactobacillus or lactic acid bacteria(LAB)- to form curd. HOW IS CURD FORMED?  LAB produce acids that coagulate and partially digest the milk proteins.  A small amount of curd (inoculum or starter )added to the fresh milk – bacteria multiplied  Milk --->curd USES OF LAB : 1. Increases vitamin B-12. 2. Checks disease causing microbes in stomach. II. BACTERIA ferment dough used for making dosa and idlis. III.Saccharomyces cerevisae (baker’s yeast) – ferment dough used for making bread . IV.” TODDY”:- A traditional drink contains plants sap fermented by microbes . V. Fish , soya bean and bamboo shoots – fermented by microbes – used as food. VI. microbes provide characteristic texture , flavor and taste to cheese varieties . Ex., (I) Swiss cheese – contains holes due to the presence of carbondi -oxide produced by Propioni bacterium sharmanaii. . (II) Roquefort cheese – ripened and flavoured by specific fungi. 1. Can you tell which metabolic path way results in the formation of carbon – di–oxide? 2. Name the bacteria used for the formation f curd? 3. Name the bacteria that produce holes on Swiss cheese? 4. Mention few uses of LAB? 5. Briefly mention role played by microbes in house hold products? MICROBES IN INDUSTRIAL PRODUCTS: Microbes are used in the preparation of beverages and antibiotics . 1. Saccharomyces cerevisae ( brower’s yeast ) ferment . Malted cereals and fruit juices - ethanol . Without distillation of the fermented broth-beer and wine distillation- whisky, brandy and rum 2. Antibiotics – penicillin streptomycin and choloromycetin . Alexander Fleming - penicillin from penicillium notatum. 3. Antibiotics used to treat plague, whooping cough , diphtheria , leprosy. 1. Can you name some other antibiotics? 2. Antibiotics cannot work against Virus. Why? III.MICROBES IN THE PRODUCTION OF CHEMICALS: S.No Type of Microbe Name of the Microbe Product Uses 1 Fungus Aspergillus niger Citric acid 2 Bacteria Acetobacter aceti Acetic acid 3 Bacteria Clostridium botulicum 4 Bacteria Lactobacillus 5 Yeast Saccharomyces cerevisae 6 Microbes Lipases (Enzyme) Used in detergents – remove oily strains 7 Microbes Pectinases Clarify bottle juices Butyric Acid Lactic acid Ethanol Proteases Streptokinases Clot buster – remove blood clots from the blood vessels of patients suffering from myocardial infarction or heart attack 8 Bacteria Streptococcus 9 Fungus Trichoderma polysporum Cyclosporin Immuno suppressive agent in organ transplantation 10 Yeast Monascus purpureus Statins Lowers the blood cholesterol ( Competitive inhibitor of the enzyme involved in cholesterol Synthesis) SEWAGE WATER TREATMENT Sewage Treatment Primary Treatment ( Physical Treatment) (Removal of particles) Sequential Filtration (Removal of Floating debris Sedimentation (Removal of Grit) Remaining sewage water Effluent (Supernatant) Primary Sludge (sedimented Solids) Secondary Treatment (Biological Treatment ) (Primary effluent) Large aeration Settling Tank Anaerobic sludge Tank digester 1. Mechanical agitation& aeration 2. Growth of flocs of aerobic microbes 3. Reduction in BOD due to the consumpt ion of organic matter by the bacteria. 4. Various treatments to reduce polluting potential. Resultant effluent sent to settling tank. Sedimentation of bacterial flocs Anaerobic digestion of bacteria & fungi. Activated sludge. Remaining activated sludge send to ana erobic sludge digester. Biogas (Energy source –mixture of methane ,H2S &CO2. Resultant effluent River streams MICROBES IN THE PRODUCTION OF BIOGAS BIOGAS-mixture of CH4,CO2 , H2O ,etc . Microbes Methanogens (methanobacterium) Action carried out Anaerobic growth on cellulose material Gas produced CH4 , CO2 ,H2 PRODUCTION OF GOBAR GAS     Biogas plant consists concrete tank (10-15 feet deep) in which slurry of dung is fed. Covered with floating cover- rise of which indicates production of biogas . Biogas produced from the tank is sent to homes through a pipe line from an out let. Spent slurry is recovered by another out let . USES OF BIOGAS 1) For cooking & lighting . 2) Slurry from biogas plant can be used as fertilizer Organisation contributed for the development of biogas production 1. Indian agricultural research institute (IARI) 2. khadi and village industries commission (KVIC) Production of Bio Gas Microbes as Bio control agents Biocontrol: use of plant diseases & pests. Biocontrol agents 1. Ladybird & dragonflies (red & black 2. Bacillus thuringiensis ( available in sockets as dried spores ) mixing with water – sprayed on the plants parts – produces toxins in the gut of larvae when it is eaten. biological methods for controlling Pests 1. Aphids & mosquitoes 2. Caterpillars of butterflies that affect brassicas & fruit trees. 3. several plant pathogens 4. Insects & arthropods. 3. Trichoderma fungus 4. baculoviruses ex: nucleopoly hedrovirus ( species specific.) Differences between pesticides & biopesticides PESTICIDES 1. Chemical in origin 2. harmful 3. pollute the environment 4. toxic BIOPESTICIDES 1.biological in origin 2.harmless 3. do not pollute. 4.non-toxic Q1 . How does Bt kill larvae of the caterpillar? Q2. Differentiate pesticides from bio pesticides. MICROBES AS BIOFERTILISER Biofertilisers : organism that enrich the the soil. nutrient quality of Sources : bacteria , fungi & cyanobacteria Biofertilisers Uses 1.Ex: Rhizobium of root nodules of leguminous plants. 1.Fix atmospheric N2→NO3 (symbiotic) 2. Azospirillum & Azobactor 2.fix atmospheric N2 →NO3 (free living ) absorbs phosphorus from soil FUNGI: Mycorrhiza passes to the plant of Glomus on which they live Resistance to root borne pathogens tolerance to salinity and drought Increase in plant growth and development Eg: Anabena and Nostoc. Oscillatoria Blue green algae Fix atmospheric nitrogen Add organic water & increase soil fertility REVIEW:Fermentor:- A large vessel in which microbes are grown. Pencillin:- An antibiotic from pencillium notatum discovered any Alexander Fleming. Ganga action plan ,Yamuma action plan:- Initiated by the Ministry of Environment and forests to save the major rivers- Ganga &Yamuna. Bt-cotton:- Cotton plant that has the toxic genes of bacillus thurin giensis which can kill the larvae of insects. Mycorrhiza:- Symbiotic associations of fungi with plants. Ernest chain & Howard Florey:- Established the potential of penicillin as an effective antibiotic. Flocs:- Masses of bacteria associated with fungal filament to form mesh like structure. QUESTIONNAIRE (2marks) 1. Name the microorganism used in the preparation of curd. How does it produce? 2. Mention any two uses of LAB? 3. Name the brewer’s yeast. What is its role? 4. Bottled fruit juices are clearer as compared to those made at home. Why? (3marks) 5. Mention any three microbes and their uses in producing house hold products? 6. What is biogas? What are its components? Name the major bacteria required for its preparation? 7. Explain briefly how biogas is prepared? 8. Explain any three microbes &their role as bio control agents? (5marks) 1. List out any five microbes and their role in the preparation of chemical, enzymes and other bioactive molecules? 2. Explain the primary and secondary treatment of sewage water treatment? 3. List out the role of microbes as biofertiliser? Unit 9 Chapter 11 BIOTECHNOLOGY – PRINCIPLES AND PROCESSES CONCEPT MAP Restriction Enzymes Polymerase enzyme Tools of rDNA technology Ligases Vectors Host 2.Cutting 1.Isolation of DNA 5.Recombinant protein Processes of rDNA technology 4.Insertion into host H.G.KHORANA Nobel Prize in Genetics 3.Amplification of gene FOREVIEW The term bio technology is the product of interaction between biology and technology. It is the controlled use of biological agents such as micro organisms or cellular components for beneficial use. Bio technology provides us with a wide range of products in considerable amounts. Some of the products are (1) Food items (2) Dairy products (3) Alcoholic beverages (4) Organic acid (5) Vitamins (6) Enzymes (7) Hormones (8) Amino acids (9) Antibiotics (10) Vaccines etc. EXPOSITION OF CONCEPTS  Principles of biotechnology  Tools of Recombinant DNA technology o Restriction Enzymes o Cloning vectors o Competent Host o Processes of Recombinant DNA technology o Isolation of the Genetic material o Cutting of DNA at specific locations o Amplification of gene of interest using PCR o Generation of Recombinant DNA into the Host Cell / organism o Obtaining the foreign gene product o Down stream processing  o Genetically modified organism  o What is GMO? What are DNA ligases? Enzymes which join the two fragments of double stranded DNA by the formation of Phospodiester bonds.  o What is cloning ? The process of producing genetically similar molecules, cells or organisms from a commom precursor is known as cloning. o Core techniques of biotechnology o Genetic engineering o Maintenance of Sterile ambience in chemical engineering processes to enable the growth of the desired microbe for the manufacture of bio technologies products like – antibiotics, vaccines , enzymes etc. Recombinant DNA = Vector + insert ( DNA Fragments ) (rDNA)  Recombinant DNA is the DNA formed by combining DNA’s from different organisms  Origin of replication which is responsible for initiating replication.  Cloning – Making multiple identical copies of any template DNA  Molecular Scissor’s – restriction enzymes o The cutting of DNA at specific locations by restriction enzymes.  A plasmid can be used as a vector to transfer a foreign piece of DNA into the host organisms.  DNA ligase – The linking of antibiotic resistance gene with the plasmid vector. CLONING: (antibiotic resistance gene in E.COLI ) The ability to multiply copies of anti biotic resistance gene in E.coli TOOLS OF RECOMBINANT DNA TECHNOLOGY  Restriction enzyme  polymerase enzyme  Ligases  Vectors  Host organism RESTRICTION ENZYMES belong to a larger class of enzymes called NUCLEASES TYPES OF NUCLEASES EXO NUCLEASE Removes nucleotides from the ends of the DNA ENDO NUCLEASE Make cuts at specific positions within the DNA Pallindromes : Group of letters that form the same words when read both forward and back ward. Eg. MALAYALAM  Restriction endonuclease are used in genetic engineering to form recombinant molecules of DNA  DNA Ligases – DNA fragments can be joined together by using DNA ligase.  Gel Electrophoresis – DNA fragments can be separated by gel electrophoresis  DNA fragments are negatively charged molecules, they can be separated by forcing them to move towards the anode under an electric field through a medium / matrix.  DNA fragments can be visualized after staining the DNA with a compound known as ethidium bromide followed by exposure to UV radiation. CLONING VECTORS: Features required to facilitate cloning into a vector  Origin of replication ( ori) (Sequence from where replication starts )  Selectable marker ( Marker helps in identifying and eliminating non – transformants & selectively permitting the growth of the transformant.  Cloning sites ( to link alien DNA vector needs recognition sites)  Vectors for cloning genes in plants and animals. Agrobacterium tumifaciens a pathogen of dicot plants in able to deliver a piece of DNA know as ‘ T- DNA’ to transform normal o o plants cells into a tumor and direct these tumor cells to produce chemicals required by the pathogen Retro viruses in animals have the ability to transform normal cells into cancerous cells Competent Host  Micro injection – recombinant DNA is directly injected into the nucleus of an animal cell. Biolistics or gene gun : Cells are bombarded with high velocity micro particles of gold or tungsten coated with DNA. Process of Recombinant DNA Technology Steps : 1. Isolation of DNA 2. Fragmentation of DNA by restriction endo nuclease 3. Isolation of a desired DNA fragment 4. Ligation of the DNA fragment into a vector 5. transferring the r DNA into the host 6. Culturing of host cells in a medium 7. Extraction of the desired product Isolation of the Genetic material ( DNA) To cut DNA with restriction enzyme it needs to be in pure form free from other macro – molecules. To break the cell open to release DNA along with other macro molecules such as RNA, proteins, polysaccharides and lipids, the bacterial cells / plants or animal tissues can be treated with enzymes such as lysozyme ( bacteria) cellulase ( plant cells ) chitinase (fungus) RNA can be removed by treatment with ribo nuclease, proteins can be removed by treatment with protease. Cutting of DNA at Specific location  Restriction enzyme digestions are performed by incubating purified DNA with the restriction enzymes  Agarose gel electrophoresis is employed to check the progression of a restriction enzyme digestion  DNA is a negatively charged molecules, it move towards the positive electrode ( anode) Amplification of Gene of interest using PCR ( Polymerase chain reaction ):  Multiple copies of the gene of interest is synthesized in vitro using two sets of primers and the enzymes DNA polymerase Insertion of Recombinant DNA into the Host Organism : If a recombinant DNA bearing gene for resistance to an anti biotic (eg. Ampicillin) is transferred into E.coli cells. The host cell become transformed into ampicillin – resistant cells. Obtaining the Foreign gene Product The cells harbouring cloned gene of interest may be grown on a small scale in the laboratory.  The bio reactors are the vessels in which raw materials are converted into specific products. Down stream Processing :  The product has to be subjected through a series of proceses like separation and purification REVIEW TERMINOLOGY  Green Revolution  RNA interference  Genetically modified organism  Genetically engineered insulin  Bt cotton  Gene Therapy  Bacillus thuringiensis  Molecular diagnosis  insecticidal protein  Transgenic animals  cry   Biotechnology includes the use of techniques for improvement Biopiracy of commercially important plants, animals and microbes.  Recombinant DNA technology involves the transfer of specific genes from one organism to another by using restriction enzymes and suitable vectors.  The enzymes involved in genetic engineering include lysing enzymes, cleaving enzymes, synthesizing enzymes, joining enzymes and alkaline phosphotases.  The most important enzymes are restriction endo nucleases which cleave DNA duplex at specific points.  Ligases act as molecular glue which join DNA fragments by forming phosphodiester bonds.  Large scale production of desired products involve use of bio reactors. QUESTIONNAIRE 1. Expand PCR A. Polymerase Chain Reaction 2. name the enzyme commonly used to dissolve the bacterial cell wall A. Lysozyme 3. What are molecular scissors? A. The restriction endonuclease which cut the DNA molecule into fragments with sticky ends. 4. What is gene gun? A. It is a method in which the plant cells are bombarded with high velocity micro particles of gold or tungsten coated with DNA. 2 mark Questions 1. What are DNA Ligases? A. DNA ligases are enzymes which join the two fragments of double stranded DNA by the formation of Phosphodiester bonds. 2. What are palindrome nucleotide sequences A. These are groups of nucleotides that form the same words when read both forward and back ward Eg. 5’ ------------- GAATTC------------------- 3’ 3’------------- C TT AAG------------------ 5’ 3. What are trans genic plants? A. Plants in which foreign gene have been introduced and stably integrated into the host DNA. It results in the synthesis of appropriate gene product by the transformed plants. 4. Draw and label the simple stirred tank bio reactor ? ( refer NCERT text book Pg.No : 204) 3 marks 1. What essential features must be present in a cloning vehicle? 2. What is the principle of PCR? 3. Give the diagrammatic representation of recombinant DNA technology? 5 marks 1. Describe the tools of recombinant DNA technology? 2. Write an account of the Principles of biotechnology? CHAPTER 12 BIO TECHNOLOGY AND ITS APPLICATIONS CONCEPT MAP Applications of Biotechnology 1. Agriculture Insecticid al protein 2. Medicine RNA interferenc e Genetic Engineerin g 3. Transgenic Animals Gene therapy FORE VIEW The application of biotechnology include therapeutics, diagnostics, genetically modified crops for agriculture, processed food , bio remediation, waste treatment and energy production. EXPOSITION OF THE CONCEPTS  Biotechnological applications in Agriculture  Bio technological applications in medicine  Transgenic Animals – Ethical issues 1. What is green revolution? 2. What is a clone? Bio technological Application in Agriculture GMO : Plants, bacteria, Fungi and animals whose genes have been altered by manipulation are called genetically modified organisms Generally modified plants have been useful in many ways Made crops more tolerant to abiotic stresses Reduced reliance on chemical pesticides Helped to reduce post harvest losses Increased efficiency of mineral usage by plants Enhanced nutritional value of food Eg. Vitamin ‘A” enriched rice. o o o o o  Bt Cotton ( Bacillus thuringiensis) Bt toxin is produced by this bacterium. The Bt toxin gene has been cloned from the bacteria and been expressed in plants to provide resistance to insects without the need for insecticides.  B. thuringiensis forms protein crystals during a particular phase of their growth.  Bt toxin protein exist as inactive protoxins but once an insect ingest the inactive toxin it is converted into an active form of toxin due to the alkaline pH of the gut which solubilise the crystals. The activated toxin binds to the surface of the midgut epithelial cells and create pores that cause cell swelling and lysis and eventually cause death of the insect.  The toxin is coded by a gene named cry.  Proteins encoded by the genes cry I Ac and cry II Ab control cotton boll worms and cry I Ab controls corn borer.  Transposons – Mobile genetic elements  Using Agro bacterium vectors, nematode specific genes were introduced into the host plant. The introduction of DNA produced both sense and anti sense RNA in the host cells. Bio Technological Applications In Medicine Genetically Engineered Insulin  Insulin consisits of two short polypeptide chains. Chains A and chain B that are linked together by disulphide bridges  In mammals including humans insluin is synthesized as a pro hormone which contains an extra stretch called C Peptide.  C peptide is not present in the mature insulin and removed during maturation into insulin. Gene Therapy    It is a collection of methods that allows correction of a gene defect that has been diagnosed in a child / embryo. Genes are inserted into a persons cells and tissues to treat a disease. Correction of a genetic defect involves delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non – functional gene. Molecular diagnosis  Recombinant DNA technology, polymerase chain reaction (PCR) and Enzyme linked Immuno – sorbent Assay ( ELISA) are the techniques used for early diagnosis of diseases  PCR is now used to detect HIV in suspected AIDS patients  It is being used to detect mutations in genes in suspected cancer patients  It is a powerful technique to identify many other genetic disorders. ELISA  It is based on antigen – anti body interaction  Infection by pathogen can be detected by the presence of antigens or by detecting the anti bodies synthesized against the pathogen. Transgenic Animals  Animals that have had their DNA manipulated to possess and express an extra gene are known as transgenic animals Benefit from transgenic animals i. Normal physiology and development ii. Study of disease iii. Biological products iv. Vaccine safety v. Chemical safety testing Bio Piracy  The use of bio resources by multinational companies and other organisations without proper authorisation from the countries and people concerned without compensatory payment REVIEW TERMINOLOGY  Genetic engineering  Gel electrophoresis  Recombinant DNA  Selectable marker  Gene cloning  Cloning sites  Gene transfer  Micro – injection  Plasmid  Biolistics or gene gun  Restriction enzyme  Polymerase chain reaction  Vector  Bio reactors.  Tools of r DNA technology  Biotechnology has a wide spread applications in the welfare of human beings  Transgenic organisms / (GMO) have been produced by introducing foreign genes into the genome of the target organisms.  Biotechnology has wide application in the field of medicine  Many pharmaceutical products have been produced by using recombinant DNA technology.  Now by using recombinant DNA technology it is possible to produce insulin which is similar to human insulin.  Bio piracy is the use of biological and genetic resources indigenous to a country by another country. QUESTIONNAIRE 1 Mark Questions 1. Name the bacteria which produce the Bt toxin? A. Bacillus thuringiensis 2. How adenosine deaminase deficiency is caused? A. It is due to the deletion of the gene for adenosine deaminase 3. What is the principle involved in ELISA A. The principle of antigen – anti body interaction 2 Marks 1. How Bt toxin work in the body of an insects A. Once an insect ingest the inactive toxin it is converted into an active form of toxin due to the alkaline pH of the gut 2. In what way the milk of a trans genic cow is better than the natural cow milk? A. The milk contained the human alpha lactalbumin and was nutritionally a more balanced product for human babies 3 Marks 1. Write a brief account of generically engineered insulin? 2. List the ways in which the genetically modified plants have been useful? 5 Marks 1. How are transgenic animals beneficial to the man kind? 2. Write an account of Bio technology and its application in gene therapy? CHAPTER 13 ORGANISMS AND POPULATIONS CONCEPT MAP ENVIRONMENT E.P.Odum Father of Ecology BIOTIC COMMUNITY + ABIOTIC FACTORS POPULATION ATTRIBUTES OF POPULATION GROWTH MODELS ORGANISM INTERACTIONS POSITIVE NEUTRAL NEGATIVE FOREVIEW ECOLOGY deals with relationships between ORGANISMS ORGANISMS ORGANISMS  ENVIRONMENT ABIOTIC *Environment BIOTIC *Survival of the organism depends on successful interactions within members of same species or between different species *Population is a group of individuals of a species in a localized geographical area *Regional variations within biomes has lead to the formation of different habitats Variation in biotic and abiotic factors in temperate forest and desert Biomes EXPOSITION OF THE CONTENT  There are several types of species ,each capable of surviving in a particular environment  According to the amount of rainfall /snow and temperature available the regions of the world have been divided into major Biomes –desert, grassland, rainforests, Tundra etc. FACTORS AFFECTING SPECIES DISTRIBUTION TEMPERATURE;  Eurythermal organisms can tolerate wide range of temperature. Stenothermal organisms can tolerate narrow range of temperature Are cockroaches stenothermal or Eurythermal? Fishes in the deep sea have low metabolic rate to conserve heat, more unsaturated fats below the skin to prevent solidification at low temperatures WATER:  All animals and plants are affected by change in quantity and quality of water  The chemical composition & pH of water affects aquatic organisms What are animals with wide tolerance to salinity called, Euryhaline or Stenohaline ?  Fresh water fishes are stenohaline. Salmon is Euryhaline LIGHT: *Photosynthesis and flowering are affected in plants Activities like storing foods, migration and reproduction are linked to photoperiod in animals. Name any component of sunlight that is harmful to organisms  SOIL Nature of soil varies depending on its origin, the climate and development of the soil  The water-holding capacity and rate of percolation also depends on its composition  Vegetation and organism distribution also depend on the nature of the soil HOW DO ORGANISMS RESPOND TO ABIOTIC FACTORS 1. REGULATE Organisms maintain a steady internal environment by physiological or behavioral mechanisms .  Eg. Humans sweat to bring down the body temperature and shiver to prevent heat loss from the body 2. CONFORM: Organisms that cannot maintain a constant body temperature or concentration of body fluids conform to the external environment 3. MIGRATE: Animals avoid unfavourable environmental temperatures by migrating to favorable environments 4. SUSPEND ACTIVITIES: Organisms suspend their activities temporarily 5. Eg Hibernation, Seeds remain dormant . Why do frogs hibernate? Adaptations: It is a physiological , behavioral or morphological feature that enables an organism to survive in its habitat successfully.  Some adaptations are genetic eg. Kangaroo rat & cactus are adapted to live in deserts  Some organisms show physiological adaptations Eg. RBC content increases at higher altitudes in humans  Biochemical adaptations are shown by organisms living in extreme temperature and pressure  Deep sea fishes have unsaturated lipids in their membranes which provides more liquidity than saturated fats .  Fishes also have TMAO {Trimethylamine oxide }, which protects pressure sensitive proteins.  Lizards , snake show behavioral adaptations by avoiding intense heat by burrowing  Allen’S Rule : Animals living in the cold regions have smaller ears to prevent loss of heat POPULATION:  A group of individuals of one species living in a well defined geographical area Population Attributes:  Birth rate: Is the ratio of the number of new births to the total number of individuals existing in the population  Death rate: Is the ratio of the number of deaths to the total number of individuals in the population  Sex ratio :Refers to the number of females to males in a population  Age Pyramid: The % of individuals of a given age when plotted gives a structure resembling a pyramid POST REPRODUCTIVE REPRODUCTIVE PRE-REPRODUCTIVE EXPANDING POST REPRODUCTIVE REPRODUCTIVE PRE-REPRODUCTIVE STABLE POST REPRODUCTIVE REPRODUCTIVE PRE-REPRODUCTIVE DECLINING  A stable population has an erect pyramid with not much variation in the numbers of all the three age groups A declining population will have lesser number of individuals in the Pre-reproductive age group.  An expanding population will have more number of individual in the Pre-reproductive age group. Age Pyramid for India  Population Density(N):Is the number of individuals of a population per unit area. It is the measure of population size in most cases  It is measured without actually counting the animals . It may be based on the number of pug marks in tiger , size of bacterial colony in a Petri dish etc POPULATION GROWTH: It is dependent on 1. Natality:Number of births during a given period (B) 2. Mortality: Number of deaths in a given period.(D) 3. Immigration: Number of individuals that have come into the population(I) 4. Emigration: Number of individuals who leave the habitat(E) Population density at a given time can be calculated using the formula N t+1 =Nt+[( B+I) –(D+E)],where Nt =population size at time t Growth Models 1. Exponential Growth 2. Logistic Growth 1. Exponential Growth 1.Resources are unlimited - Growth is in geometric proportion - A J shaped growth curve is expected - The rate of increase in population size N after time t: dN/dt=rN,where r is birth rate - death rate (known as intrinsic rate of natural increase) 2. Logistic Growth:Verhulst- Pearl Logistic Growth - Takes place when resources are limited - Growth is initially slow and then accelerates ,decelerates and then becomes almost stationary, when it reaches the carrying capacity - It assumes a sigmoid growth curve Carrying capacity is the maximum number of individuals that can be supported in an environment. {k} Sigmoid growth curve Population Interactions: Species interact among themselves- Intraspecific They interact between one another-Interspecific The interactions may be beneficial, detrimental, or neutral. S.No Association .1 .2 Mutualism Commensalism Effect on species Beneficial Beneficial Effect on species Beneficial Neutral 3. 4. Predation Parasitism Beneficial Beneficial Negative Negative 5. Ammensalism Negative Neutral 6. Competition Negative Negative What is common to parasitism, Predation , commensalism? Example Lichens Suckerfish-shark Tiger-deer Humantapeworm Lactic acid bacteria prevents growth of other microbes Two birds on the same tree 1.Predation:  Keeps prey population in check  Reduces intensity of competition among different prey species  The number of predators comes down with decrease in prey population  Prey species adopt defence mechanisms to reduce predation Eg. Camouflage, Bad taste.  Plant preys produce chemicals that inhibit feeding Eg. Opium Calotropis-Chemicals produced- it prevents browsing by cows Frog: Deceptive colouration to avoid detection. 2.Competition:  Occurs between related or unrelated species for the same resource  The superior species would eliminate the inferior one,when two closely related species coexist {Competitive exclusion principle}  Species adopt changes in feeding patterns to avoid competition for the same resource –food 3.Parasitism:  Most parasites are host specific  Host and parasite coexist  One or more intermediate hosts may be used by the parasite to complete its lifecycle  Parasites reduce the survival and growth of the host and reduce their population density  The hosts are made physically weak and vulnerable to predators Why have harmless parasites not evolved in nature ? 4. Commensalism: One partner is benefited ,other neither harmed nor benefited. Epiphytes growing on trees are commensals. 5. Mutualism:  Both partners are benefited  Both the species co-evolve  Eg Plants and pollinating insects LIFE HISTORY VARIATION : Every species has evolved a strategy of reproduction ,which is most efficient for it in its habitat Variation in this strategy occurs due to abiotic and biotic limiatations in its habitat REVIEW : Terminology; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Phytophagous Interference competition Competitive release Competitive exclusion principle. Resource patitioning Brood parasitism Diapause Eurythermal/Stenothermal Euryhaline/stenohaline Natality 11. Mortality 12. Logistic growth 13. Darwinian fitness 14. Population density 15. Intrinsic rate of natural increase Questionnaire 1. Salmon lives in both fresh water and marine water . Is it Stenohaline or Euryhaline? 1 2. What is the Biological control of pests based on? 1 3. How does immigration effect population size 1 4. Give two strategies of Eurythermal organisms to withstand extreme temperatures 2 5. Why do cows avoid feeding on calotropis? 2 6. How do underwater invertebrates withstand high external pressure 7. What does the r value in population growth signify? 8. How does carrying capacity affect population growth? 9. Predators in Nature are prudent . Explain 2 10. Competitions does not always occur between related species. Justify 11. Explain “competitive release” 12. Mosquito is a blood feeder ,yet it is not considered as parasite . Why? 13. What is the sexual deceit tactic of Ophrys, an orchid? 2 14. Competition occurs even if resources are limited. Explain with an example. 15. What are the differences in the two models of population growth? 16. Represent the population density at time t+1 with an equation . Explain each term 3 17. What are the attributes of Population ? Say how the age pyramids reflect a declining ,stable and an expanding population? 5 *********************************** CHAPTER 14. ECOSYSTEM CONCEPT MAP Abiotic Ecosystem Structure Ecological Successor Productivity Biotic Decompositio n Ecological Pyramids Ecosystem Services Energy Flow Function Nutrient Cycling FOREVIEW: ECOSYSTEM Terrestrial Aquatic anmade Functions of Ecosystem (i) Productivity (ii) Energy Flow (iii) Decomposition (iv) Nutrient Cycling Ecological Pyramids (i) Pyramid of number (ii) Pyramid of Biomass (iii) Pyramid of Energy Primary Hydrarch Ecological Succession Secondary Xerarch Gaseous Nutrient Cycles Sedimentary EXPOSITION OF CONCEPTS Ecosystem Structure: Includes Biotic & abiotic components STRATIFICATION : Different species occupy different levels in the Ecosystem Ex., Trees in a tropical forest. Is stratification seen in oceans ? Ecosystem functions: 1. Productivity Solar Energy Chemical Energy Autotrophs 2. Decomposition : Organic molecules in dead plants & animals Detritivores , fungi & bacteria Inorganic molecules in soil& atmosphere for reuse 3. Energy Flow: Energy flows from the sun to the producers and then to the consumers and decomposers through the food chain 4. Nutrient Cycling : Cycling of nutrients through biotic & abiotic components of the ecosystem Productivity Rate of biomass production in an ecosystem, expressed as g-2 yr-1 Primary Productivity: Biomass production /unit area over a time period by autotrophs What factors can affect Primary productivity? Gross Primary Productivity- Biomass produced /unit area /unit time Some of this GPP is lost during respiration . GPP-respiration=NPP(Net Primary Productivity) The available biomass for herbivores is GPP or NPP? Sugars Gross Photosynthesis CO2 Oxygen Leaf Respiration (R) CO2 Whole Plant Construction & Maintenance Respiration (R) CO2 Net Photosynthesis Net Primary Production (NPP) Dead Organic Matter (Litter) Heterotrophic Consumption Remaining Plant Biomass ENERGY FLOW Assimilation Excretion Secondary Productivity: It is the rate at which consumers form new organic matter, using food consumed. Why does Productivity vary in different Ecosystems.  Productivity is higher on land than in Oceans because of (i) The greater number of autotrophs and (ii) Better availability of sunlight and nutrients for plants. Decomposition :  Organic Molecules Inorganic CO2, H2O Events in Decomposition : The following processes take place simultaneously 1. Fragmentation : Breaking down of detritus into Detritivores 2. Leaching : Precipitation of water soluble inorganic nutrients into the soil 3. Catabolism : Degradation of detritus by the action of enzymes of fungi and bacteria Detritus Fragmentation Catabolism Leaching Humus is a dark coloured amorphous substance resistant to microbial attacks formed during decomposition Degradation of humus is slow and releases mineral nutrients Why is humus called a reservoirs of minerals? Oxygen availability detritus Composition of Factors affecting Decomposition Temperature Soil moisture Which would decompose quicker? Lignin or Soluble sugars? Energy Flow : Characterisitcs of Energy Flow :1. 2. 3. 4. 5. Undirectional Flows from sun to producers From one trophic level to next higher level Loss of energy , before transfer to next level Flows through food chain Grazing Food Chain Detritus Construct a food chain with an organism as link between detritus and Grazing food chain Ecological Pyramids Represents the relationship between different trophic levels in an ecosystem ,in terms of number, biomass and energy. An ideal pyramid of number has the total number of producers at the base , primary consumer, Secondary Consumer, Tertiary Consumers at the successive levels towards the apex Types of Pyramids – Pyramids of energy, number, biomass.  Pyramid of Energy is always upright as energy transfer involves loss of energy at each step  Ecological pyramids do not consider Saprophytes  Ecological pyramids do not consider same species at different trophic levels. When would you get an inverted pyramid of number? Ecological Succession : Is a gradual change in species- composition in a given area  The communities keep changing according to environmental changes  The entire sequence of communities that change are called sere.  Biomass increases in successive communities.  The first species that invade a bar place are the Pioneer species.  The final community that is in equilibrium with the environment is the climax community. Can the process of Succession and evolution be parallel processes? Primary Succession : It starts on a place where organisms never existed Eg. Bare rocks Succession Secondary Succession : It occurs in a place where the existing organisms were lost due to floods, fire etc. Eg. Forests. after fire. In which form of Succession ,climax would be reached faster. Why? Xerarch( starts on dry land) Succession Hydrarch(starts In water) Xerarch Hydrarch Bare newly formed pond rock Lichens Phytoplankton Enzymes cause weathering of rocks, soil forms Bryophytes Free floating angiospersms Bigger Plants Rooted hydrophyte Marsh- medow ( sedges)_ Grasses Trees Nutrient Cycling :Bio- geo chemical cycle : Is the movement of nutrient elements through the biotic and abiotic components of an ecosystem. Gaseous – Nutrient reservoir is atmosphere Types of cycles Sedimentary – Crust of earth is the reservoir Factors affecting Nutrient Cycles : 1. pH , Soil, temperature, moisture Carbon Cycle Phosphorous Cycle: What is the importance of reservoir in nutrient cycles. Differences between Carbon & Phosphorous Cycles Carbon Phosphorous 1. Gaseous exchange involved No gaseous exchange involved 2. Input through rainfall high Low input through rainfall 3. Not much loss as sediments Most of it lost from cycling due to sedimentation Products of Ecosystem processes: 1. Forest ecosystem purify air and water 2. Minimize drought and floods 3. Cycling of nutrients 4. Generate fertile soil 5. Habitat for wild life 6. Maintain bio diversity Review Terminology 1. Saprotrophs 2. Humification 3. Food web 4. Standing crop 5. Standing state 6. Fragmentation 7. Trophic level 8. Stratification 9. Productivity 10. GPP, NPP 11. Hydrarch 12. Xerarch 13. Ecological succession 14. Climax community 15. Sere 16. Pioneer species 17. GFC, DFC Questionnaire 1. Name the process which fixes carbon in nature (1) 2. Why is the pyramid of biomass in the sea ,inverted? (1) 3. Man at the 2nd trophic level is at an advantage over a man at the 4th trophic level why? (2) 4. Why does detritus build up in the soil and low temperature and dry conditions . (2) 5. What would happen if a succession is disturbed by fire out break. (2) 6. On what two factors does the “Standing state “ depend? (2) 7. Give 2 instances how human activities affect carbon cycle. (2) 8. Give two differences between Phosphorous and carbon cycle (2) 9. What does the standing state of Nutrients depend on (2) 10. How does human interference affect primary succession? (2) 11. In Pyramid of Biomass, dry weight is preferred to fresh weight why? When is this pyramid inverted. (2) 12. What are the limitations of ecological Pyramids. (2) 13. Why are trophic levels restricted in GFC’s. (2) 14. What is the percentage of energy incident and absorbed by green plants for photosynthesis. How does it flows through the trophic levels. Represent it in a flow chart. (5) Chapter : 15 BIODIVERSITY AND CONSERVATION CONCEPT MAP Loss Cause Conservation In-situ Effect Ex-situ Global Biodiversity Importance Levels Patterns Latitudinal Gradients Species – Area Relation ship FOREVIEW:1. Biodiversity is the heterogeneity existing at all levels of organization in the Biosphere. Genetic Biodiversity Species Ecological Recorded Biodiversity 22% plants 70% others animals Patterns of Diversity 1. Latitudinal gradient – Diversity of Species along the latitudes 2. Species – Area relationship : Species Richness increases with increasing area with in a region up to a limit. Causes of Bio diversity Losses: 1. Habitat Loss of Fragmentation 2. Over exploitation of Natural resources Causes of Biodiversity Loss 3. Invasion by alien species 4. Co – extinction  Extinction of one ,causes extinction of the other associated organism Need for Biodiversity Conservation : Narrow 1. Utility Broad 2. Ethical In situ– In the natural habitat itself Conservation Ex – situ – Away from natural habitat EXPOSITION OF THE CONCEPTS:Biodiversity exists at different levels of biological organization Genetic diversity refers to diversity of genes rather a species Species diversity : Diversity at the level of species. The different forms of species existing in a region. Ecological diversity : Refers to the diverse ecosystems. Each one with its typical abiotic factors and biotic forms. Species richness in India 1. Of the 7 million global species estimated more than 70% are animals Why are the more animals than plants species? 2. The number of fungi species is more than the combined total of the species of fishes, amphibians, reptiles and mammals 3. India has about 8.1% of global species diversity 4. More than 1,00,000 plants species and more than 3,00,000 animals species are yet to be discovered. Patterns of Bio diversity: I Latitudinal Gradients : 1. Species diversity is not uniform through out the world 2. It decreases as we move away from the equator towards the poles 3. Tropics have more diversity due to the following reasons (i) The climatic conditions in the tropical latitudes remained undisturbed for many years unlike in the temperate regions (ii) Environment in the tropics is more constant and predictable where as in the temperate ones show seasonal variation. Hence in tropics niches become specialized and lead to greater species diversity. (iii) More productivity due to the availability of more solar energy. Species – Area relationship : 1. Species richness increases with increasing area but only to a limit 2. With logarithmic increase in area , the species richness also increases logarithmically. 3. Over very large areas, the increase in area shows greater increase in species richness. Importance of species diversity:1. Species diversity leads to stability of the ecosystem 2. A stable community is one (a) which is resistant to disturbances in the ecosystem (b) which does not show much variation in productivity year after year (c) which is resistant to invasions by alien species. Loss of Biodiversity : Human activities are the main cause of rapid extinction  There has been 5 episodes of mass extinction before the present sixth extinction that is in progress  Nearly half of all species might be wiped out with in the next 100 years if the present trend continues. Biodiversity loss leads to 1. Decline in plant production 2. Lowered resistance to environmentaldisturbances like drought 3. Processes like plant productivity, use of water diseases and affect of pests may be affected. Causes of Biodiversity Loss :The Evil Quartet : Four major causes of biodiversity loss 2. Habitat loss and fragmentation :a. Destruction of habitat b. Degradation of habitats by pollution c. Breaking up of large habitats due to human activities affect mammals, migration leads to population decline 3. Invasion by alien species :Foreign species introduced to an environment can pose threat to the native species. Eg. Eichornia , African cat fish 4. Co-extinctions :When one species becomes extinct other plants and animals associated with it also become extinct Eg. When a host fish becomes extinct it parasite also may face extinction 5. Over – exploitation :- over use of many species of plants and animals are responsible for their extinction What must be the reason why alien species threaten native ones to extinction? 6. Need for Biodiversity Conservation : 1. Humans get economic benefits from nature through food, firewood, medicines, lubricants, perfumes , drugs etc. 2. Ecosystem services like pollination, influence of climate factors , oxygen supply 3. Ethical reason- we have a moral responsibility to conserve the Natural Resources Conservation strategies 6. In-situ Conservation : Species are conserved in its natural habitat  Certain areas have been identified for maximum protection  They are ‘ Biodiversity hotspots’ region with very high levels of species richness and species that are endemic( seen only in that region and no where else)  Habitat loss is at a rapid pace in these regions Why is the Western Ghats identified as a ‘hot spot’ of Biodiversity?  34 hot spots have been identified in the world  Strict protection can bring down mass extinctions in these regions  Biosphere, reserves, national parks, sanctuaries and sacred groves are biodiversity rich and are legally protected in India. 7. Ex-situ Conservation : Threatened animals & Plants are protected in special places  Zoological parks, botanical gardens,cryopresevation ( stored at very low temperatures) of gametes, seed banks, tissue culture are a few strategies for exsitu conservation.  Red list ,documents species in different levels of threat that need to be protected REVIEW Terminology 1. Genetic diversity 2. Species diversity 3. Co – extinctions 4. Hot spots 5. The Evil Quartet 6. Red list Questionnaire 1. Rauwolfia vomitoria plant in Himalayan ranges show differenes in potency and concentration of Reserpine, a chemical. Account for this difference. (1) 2 .What is the estimated global species diversity of Robert May? (1) 3. Why is India in the group of 12 Mega diversity countries? (1) 4. Name any 2 examples of recent extinctions 5. What does the IUCN Red list 2004, document? (1) (1) 6. Cryopreservation is an exsitu conservation strategy. Explain. (2) 7. How is a region identified as a ‘ Hot- Spot ‘ of Biodiversity? (2) 8. Why are there no estimates for prokaryotic species? (2) 9. Tropics show greater biodiversity compared to temperate regions. Why? (3) 10. What was Alexander Von Humboldt’s discovery with regard to Species – area relation ship. Explain . (3) 11. Give 3 reasons why Biodiversity need to be conserved? (3) 12. What is referred to as ‘Sixth extinction’? How and why is it different from the earlier five? ` (3) 13. Explain what ‘The Evil quartet’ in Biodiversity loss, refers to? 14. What are sacred grooves? What is their significance? **************** (3) (3) CHAPTER 16 ENVIRONMENTAL ISSUES CONCEPT MAP Environmental issues Pollution Ozone depletion Air Degradation of natural resources Green house effect Water CFC FC Deforestation Noise Land Industrial waste Solid waste Radio active waste Global warming Reforestation FORE VIEW  Pollution is any undesirable change in physical, Chemical or biological characteristics of air, land, or water.  Agents that bring such undesirable change are called pollutants.  Government of India passed the Environment (Protection) Act 1986 to control environmental pollution, to protect and improve the quality of our environment. EXPOSITION OF THE CONCEPTS  Air Pollution  Noise Pollution  Water Pollution  Industrial Wastes  Solid wastes  Agro-chemical wastes  Radio-active wastes  Radiation  Green House Effect  Global warming  Ozone Depletion  Degradation of Natural Resources  Deforestation  Reforestation  Review . Air Pollution  Air pollution cause injury to all living organisms.  Harmful effects depends on the concentration of Pollutants, duration of exposure and the organisms  Smoke stacks of thermal power plants, smelters and other industries release particulate and gaseous air pollutants, they are to be filtered out before releasing to the atmosphere.  Electrostatic Precipitator :- its is used to remove particulate matter in industries.  As per Central Pollution Control Board (CPCB) particulate size 2.5 micrometers or less in diameter (P.M.2.5) are harmful to health.  Automobiles are a major causes of air pollution. Proper maintenance, use of lead – free petrol or diesel can reduce pollutants from automobiles  Catalytic converters, having metals like platinum – palladium – rhodium as catalysts – fitted to automobiles reduces the emission of poisonous gases  Compressed natural gas (CNG) is better than petrol or diesel, because it burns most efficiently and very little of it is left unburnt. Steps taken by the Government :  The Government of India through a new auto fuel policy has laid out a road map to reduce pollution in Indian cities, to reduce sulphur to 50ppm in petrol and diesel.  Governments are trying to reduce uses of plastics and use eco friendly packaging.  Euro II norms(The Bharat stage II Equivalent to Eureo II norms ) stipulates that sulphur be controlled at 350 ppm in diesel and 150 ppm in petrol and automatic hydrocarbons 42% in the fuel.  Euro III emission specification all automobiles fuels have to met in the major eleven cities from 1st April, 2005 .  Eureo IV norms by April 2010. Noise Pollution  Air (Prevention and Control of Pollution), Act enforced in 1981, amended in 1987 to include noise as an air pollutant.  Exposure to high sound level, 150 dB or more damages the ear drum, causes psychological and Physiological disorders in man. Water pollution Human being has been abusing the water bodies. The Government of India has passed the water Prevention and Control of Pollution / Act 1974, to safeguard water resources. Domestic:  0.1% impurities make domestic sewage unfit for human use.  It is possible to estimate the amount of organic matter in sewage water by measuring Biochemical oxygen Demand ( BOD).  Effects of sewage discharge on important characteristics of a river – results in a sharp decline in dissolved oxygen causes mortality of fishes and other aquatic creatures.  Presence of large amounts of nutrients in water cause excessive growth of planktonic ( free –floating) algae – called algal bloom, which result in deterioration of water quality.  Eg. Water hyacinth (Eichhornia Crassipes) the world’s most problematic aquatic weed called “Terror of Bengal” lead to imbalance in ecosystem. Industrial waste waters :  Toxic substances, present in industrial waste waters can undergo bio magnification in the aquatic food chain.  Biomagnification refers to increase in concentration of toxicant at  Eutrophication is the natural aging of a lake by biological enrichment of its water. Effluents from the industries and homes can radically accelerate the aging process is called cultural or accelerated Eutrophication.  Thermal waste water from electricity generating units eliminates the organisms sensitive to high temperature. Solid Wastes :  Municipal solid wastes from homes , hospitals, Schools, Shops etc collected and disposed by the municipality often cause breeding ground for rats and flies.  Sanitary land fills – wastes are dumped in a depression or trench after compaction but there is danger of seepage of chemicals etc from land fills. Polluting the underground water sources Wastes can be categorized into there types a) Bio – degradable b) Recyclable c) Non biodegradable  Irreparable computers and other electronic goods are known as electronic wastes. E-wastes are buried in land fills  Recycling is the only solution for the treatment of e-wastes in an environment friendly manner. Agro Chemicals : Increased use of Inorganic fertilizers, pesticides, herbicides, fungicides etc are toxic to non tar gent organisms – the important components of soil ecosystem  Agro chemicals affect the aquatic ecosystem and causes eutrophication. Radio active wastes:  Nuclear energy hailed as a non – polluting way for generating electricity.  Nuclear energy has two very serious inherent problems. (1) Accidental leakage ( Like three Mile Island and chernobil incident) (2) Safe disposal of radio active – wastes ( in shielded containers buried with in rocks 500m deep below earth surface).  Radiation given off by nuclear wastes damages biological organisms because it causes high rate mutations.  Nuclear radiation causes various disorders and diseases like cancer. Green House effect and Global warming: Green house effect is a naturally occurring phenomenon responsible for heating the Earth’s surface and atmosphere.  Earth’s surface re-emits heat in the form of infra red radiation. Gases like CO2 and CH4 (called green house gases responsible for green house effect.) radiates heat energy and comes to earth surface heating it once again.  Increase in the level of green houses gases leads to global warming, which results in environmental changes and odd climates  Eg. El, Nino effect. This rise n temperature melts polar ice caps and Himalayan snow caps, may result in a rise in sea level that can submerge coastal areas. Control measures - Cutting down the use of fossil fuels - Reduce deforestation - Reduce the emission of green house gases to atmosphere. Ozone Pollution  “Bad” ozone formed in the lower atmosphere (Troposhere) harm plants and animals.  “Good” ozone found in the upper part of the atmosphere is called stratosphere shield absorbing UV radiation from the sun. The thickness of ozone is measured in terms of Dobson units (DU)  Ozone is continuously formed by the action of UV rays on molecular oxygen and also degraded into molecular oxygen in the stratosphere.  There should be a balance between production and degradation of ozone in the stratosphere. The balance is disrupted by chlorofluoro carbons (CFCs) using in refrigerants. Cl degrades ozone and produces molecular oxygen.  Ozone depletion occuring widely in stratosphere particularly marked over Antarctic region. Large area of thinned ozone layer is called ozone hole.  UV – B damages DNA mutation may occur. UV-B causes inflammation of cornea called snow-blindness cataract.  International treaty called Montreal protocol was signed at Montreal (Canada) in 1987 to control the emission of ozone depleting substances. Subsequently may efforts are made to reduce the emission of CFCs and other ozone depleting chemicals. Degradation of natural resources: By improper resource utilization practices. 1. Soil erosion and deforestation 2. Water logging and soil salinity. Deforestation –  Conservation of forest areas into non-forest areas like agricultural land. National Forest Policy (1988) of India has recommended 33% forest cover for the plains and 67% for the hills.  Slash & burn agriculture called Jhum Cultivation in the most eastern states of India contributed to deforestation. Reforestation  Reforestation is the process of restoring a forest by planting trees.  Government of India instituted the Amrita Devi Bishmoi Wildlife Protection Award for individual or communities from the rural areas that have shown extra ordinary coverage in protecting wild life.  Chipko movement of Garhwal Himalayas in 1974 – bravery in protecting trees from the axe.  JFM. Joint Forest Management – In 1980, Government of India introduced JFM to work closely communities for protecting the forests. ABBREVIATIONS CPCB – Central Pollution Control Board CNG – Compressed Natural Gas BOD – Biochemical Oxygen Demand JFM – Joint Forest Management e- waste – electronic waste with the local REVIEW : 1. Draw, label explain the working of an electrostatic precipitator. 2. Define pollution? What are pollutants. Give Examples. 3. Write the full form of CPCB and CNG. 4. What are the different types of air pollutions? What are the various steps to control it? 5. Explain the different types of water pollutions? What are the various measures taken to control it? 6. Explain with examples : a. Eutrophication. b. Municipal solid wastes. c. Sanitary land fills. d. Agro chemicals. 7. Give an account of the Radio active wastes and their management. 8. Explain briefly a. Green house effect. b. Global warming. 9. Write a note on Ozone depletion. 10. Briefly explain : a. Degradation of natural resources. b. Deforestation. ************** MODEL PAPER(SOLVED) – 1 BLUE PRINT Knowledge VSA UNIT VI(12) SA I SA II 2(1) UNIT VII(20) 1(1) UNIT VIII(12) 1(1) 2(1) Total LA VSA 2(1)* 1(1) SA I 3(1) 3(1) 1(3) 5(1) 1(1) 20 SA II Application LA 3(1) 3(1) UNIT IX(12) UNIT X (14) Understanding VSA SA I SA II Skill L A VS A SA I SA II 3(1) * 1(1) 5(1) 2(2) 2(1) 2(1) 3(1) 2(1) 3(1) 2(1) 2(1) 3(2) 3(2) 30 15 3(1) 5 LA MODEL PAPER(SOLVED) - 1 Time : 3 Hours Max.Marks : 70 General Instructions i. ii. iii. iv. v. vi. vii. This Question paper consists of four sections, A,B,C and D. Section A contains 8 questions of one mark each , Section B is of 10 Questions of two marks each Section C is of 9 questions of three marks each and Section D is of 3 Questions of five marks each. All questions are Compulsory There is no overall choice. However, an internal choice has been provided in one question of 2 Marks, one Question of 3 marks and all three questions of 5 Marks. You have to attempt only one of the choices in such questions. Question number 1 to 8 are to be answered in one word or in one sentence each Question number 9 to 18 are to be answered in approximately 20 – 30 words each. Question number 19 to 27 are to be answered in approximately 30 – 50 words each. Question number 28 to 30 are to be answered in approximately 80 – 120 words each. SECTION –A (1 MARK ) 1. If the number of chromosomes of a wheat plant is 26 ,how many chromosomes does the endosperm have ? 2. What is sterilization ? 3. A double stranded DNA has 40 percent of adenine ,calculate the percent of guanine in the DNA . 4. Write the causal agent of amoebiasis . 5. Name one strategy for ex-situ conservation . 6. What causes withdrawal symptoms? 7. Why is Rheumatoid arthritis is known as autoimmune diseases 8. How can we evolve a pureline in any animals SECTION - B ( 2 MARKS ) 9. What are the devices developed by flowering plants to encourage cross pollination ?(any two) 10. A child has blood group B .If the father has blood group O and mother blood group B. Work out the genotypes of the parents and the possible genotypes of the other offsprings . 11. Draw the replicating fork of a DNA molecule 12. A black eyed father married blue eyed mother and all the children were black eyed ,where black is dominant over blue .Write the possible genotypes of parent and the children . What is this type of cross referred as ? 13. Differences between phosphorus and carbon cycle . OR What is a standing state of nutrients depend on ? 14. Enumerate the ecosystem services (any two ) 15. What are endonucleases ? 16. What is somatic hybridization ?Explain with an example . 17. Whether insulin can be administered to diabetic people orally ?Why 18. A mother gave birth to a child with furrowed tongue , partially open mouth , short statured with small round head . Name the disease the child is suffering from . What is its cause ? SECTION –C (3 MARKS) 19. Mention the significance of the following : a. Sertoli cells . b. Scrotum . c.Corpus luteum . 20. Explain the cause and the symptoms of the following diseases : a. Haemophilia . b.Sickle –cell anaemia c.Phenylketonuria. 21. Explain homologous organs with an example from plants and animals. 22. Schematically describe the replication of retrovirus . 23. There are problems associated with the overuse of chemical pesticides and there is a large pressure to switch to use of biocontrol agent .Explain with an example . 24. What is referred to as “EVIL QUARTET” with regard to biodiversity loss? 25. What is a single cell protein ? Explain the method of growing Spirulina and nutrient content of Spirulina . 26. Why is secondary succession faster than primary succession ? What would happen if the secondary succession is interrupted by human 27. What are the different ways by which organisms respond to abiotic factors .Explain any three . OR What are the criteria for the hotspots ?Name any three hotspots . SECTION –D (5 MARKS ) 28. a) Explain the monosporic development of female gametophyte . b) Draw a neat labelled sketch of a diagrammatic representation of the mature embryo sac. OR a) Explain the process of spermatogenesis in humans . b) Draw a neat labeled structure of a sperm . 29. How did Messelson and Stahl prove that the DNA replication is a semiconservative method of replication . OR Briefly describe the following : a) Convergent evolution . b) Adaptive radiation . c) Founder effect . d) Codominance . e) Transcription . 30. Explain the following terms : a) Biopiracy . b) Transgenic animals . c) Transformation . d) Palindromic nucleotide sequence . e) Gene gun . OR Describe the steps involved in Polymerase chain reaction . Answer Key Section A 1 (39) 1 2. Surgical method to prevent any more pregnancies, by blocking gamete transport ½ + 1/2 3. 10 percent of Guanine 1 4. Entamoeba histolytica 1 5. Zoological parks, botanical garden, wild life, safari parks, preserving viable gametes , seed banks ( any one) 1 6. Abrupt discontinuation of drug/alcohol 7. Attacks self cell 8. Homozygosity by inbreeding Section B 9. Pollen release and stigma receptivity are not synchronized Anther and Stigma are placed at different positions self in – compatibility unisexual flowers ( any two ) 10. Father (O) ii Mother(B) IBi Child B 5’ i Child o IBi 11. 1 IB i 1+1 ii 1+1=2 3’ Template DNA ( Parental Strands) ½x4=2 ’ 3’ continuous Synthesis 3’ 5’ Discountinuous Synthesis Newly synthesized strands 3’ 5’ 12. Parent Man Bb B b Woman bb b 1 Bb Black bb blue Test Cross 1 13 1. Atmospheric inputs of phosphorus through rainfall are much smaller than carbon inputs 2. Gaseous exchanges of Phosphorus between organism and environment are negligible or Type of ecosystem and season 1+1 14. Healthy forest ecosystems purify air and water, mitigate droughts and floods, cycle nutrients, generate fertile soil or any other ( any two) 1 + 1 15. Make cuts at specific positions with in the DNA 1+1 16. Isolated protoplasts from two different varities of plants – each having a desirable character – can be fused to get hybrid protoplasts – further grown to form a new plant. This process is called somatic hybridation. Tomato and potato. 1+1 17. No. Insulin consists of two short polypeptide chains.It will be digested by proteases if taken orally. 1+1 18. Down’s Syndrome. Trisomy of 21 1+1 19. a. Nourishes sperms b, Maintaining 2oC less than body temp for spermatogenesis 1+1+1 c. Secreting progesterons 20. a. Sex – linked recessive diseases, non – stop bleeding b. autosome linked recessive trait, sickle cell, low oxygen tension c. inborn error of metabolism 1+1+1 absence of enzyme converting phenylal anine to tyrosine – mental retardation 21. Similar anatomical structure but perform different functions. vertebrate fore limbs , hearts or brain, thorn and tendrils of Bougainvillea and cucurbita. 1 + 1 +1 22. Retrovirus infect & normal cells (animal cells) Viral RNA introduced Incorporates into host Genome Viral DNA is produced by reverse transcriptase ½x6=3 New viral RNA Produced by Cell New virus Produced infect other cells 23. Use of bio control agent will greatly reduce one dependence on toxic chemicals and pesticides. Eg. Bacillus thuringiensis spores mixed with water and sprayed – kills insects larvae 1 + 1 +1 24. Habitat loss and fragmentation – cutting and clearing the forests , degradation by pollution. over exploitation -of natural resources 1+1+1 Alien species invasion -causes decline or extinction of indigenous species Co-extinctions - causes associated plants and animals also become extinct. 25. Single cell protein is growing microbes on an industrial scale as source of good protein for animal and human nutrition  Spirulina can be grown on materials like waste water, from potato processing plants ( contain starch ) straw, molasses, animal manure and even sewage. 1 + 1 +1  Rich in protein minerals, fats, carbohydrate and vitamins. 26. Soil is already there – so rate is faster – climax reached quickly------- convert particular seral stage of succession to an earlier stages, encourage some species, discourage other species. 1+1+1 27. Temperature eury thermal, stenothermal, water euryhaline, stenohaline, light ( Photoperiod) (any three) 1 + 1+1 or 1. High levels of species richness, high degree of endemism , western Ghats and Srilanka, Indo- Burma and Himalaya 1+1+1 28. a) Nucellus MMC Megaspores One functional 8 Nucleate Egg Apparatus Antipodal Cell b) Diagrammatic embryo sac Antipodal cells Polar nuclei Egg apparatus OR Polar nuclei 1+ 1 3 1 1 1 Ref. Fig 2.8 ( c ) a) Spermatogonia Mitosis differentiation Primary Spermatocyte 1 Meiosis I Sec Spermatocytes Meiosis II 1 Spermatids Spermiogenesis Sperm b) Structure of a sperm ( Ref fig 3.6) Acrosome Nucleus Head Mitochondria – Middle piece Tail 3 29. Incorporation of heavy Isotopes of nitrogen CsCl density gradient Grown on Normal Medium I Generation intermediate density II Generation Light DNA 1 1 1 1 1 or (i) Similar adaptive features of different groups of organisms to a similar habitat 1 (ii) Evolution of different species in a given geographical area starting from a point and radiating to other areas 1 (iii) Effects of Original drifted population 1 (iv) Hybrid resembling both parents . Both the characters are inherited and present in a single individual 1 (v) Copying genetic information from one strand of DNA into RNA. 1 30. a) Use of bio – resources by multinational companies and other organizations without proper authorization b) Animals that have had their DNA manipulated to possess and express an extra gene 1 c) A piece of DNA is introduced in a host bacterium 1 d) Sequence of base pairs that reads on the two strands when orientation of reading is kept the same 1 e) Bombarding the cell with high velocity micro – particular of gold or tungsten coated with DNA. 1 OR Denaturation – region to be amplified is subjected to high temperature induced denaturation 2 Primer annealing : fragment is used to ligate with a vector 1 Extension of primer DNA polymerase 1 Amplified 1 MODEL PAPER (SOLVED) - II BLUE PRINT Knowledge VSA UNI T6 UNI T7 SA I SA II Understanding LA SA I 2(1) 1(1) SA II 2(1) 3(1) 1(1) 3(2) 1(1) UNI T9 2(1) UNI T 10 2(1) LA VSA 3(1) UNI T8 Tota l VSA Application 3(1) 20 5(1) 2(1) 3(1) 30 LA VSA SA I SA II 2(1) 3(1) 2(1) 1(1) 3(1) 1(1) SA II 2(1) 5(1) 5(1) SA I Skill 2(1) 3(1) 2(1) 1 (3) 15 5 LA MODEL PAPER (SOLVED) - II General Instructions viii. This Question paper consists of four sections, A,B,C and D. Section A contains 8 questions of one mark each , Section B is of 10 Questions of two marks each Section C is of 9 questions of three marks each and Section D is of 3 Questions of five marks each. ix. x. All questions are Compulsory There is no overall choice. However, an internal choice has been provided in one question of 2 Marks, one Question of 3 marks and all three questions of 5 Marks. You have to attempt only one of the choices in such questions. xi. Question number 1 to 8 are to be answered in one word or in one sentence each xii. Question number 9 to 18 are to be answered in approximately 20 – 30 words each. xiii. Question number 19 to 27 are to be answered in approximately 30 – 50 words each. xiv. Question number 28 to 30 are to be answered in approximately 80 – 120 words each. Section A 1. Why is a test cross perfomed? 2. What causes algal bloom? 3. A patient suffering from sneezing, watering was treated antihistamine. What is the diagnosis? 4. What phenomenon do Darwin’s finches represent? 5. How does typhoid fever spread? 6. The Nile perch introduced into Lake Victoria caused extinction of certain fishes. Why? 7. Why are different class of algae seen at different depths in the oceans? 8. In earthworm inhabited soil, decomposition is faster why? Section B 9. Why is apple a false fruit? How is a true fruit different? 10. Draw a labeled diagram showing stages of microscope maturing into a pollen grain 11 What are staminate and pistil late flowers? What gametes do they produce? 12 Describe the development that follows the formation of zygote in humans up to implantation? 13 Name the enzymes used to lyse cells of release DNA from bacteria and fungal cells. 14. How do Gross primary productivity differ from Net primary productivity? 2 15. DNA replication involves continuous and discontinuous synthesis. Explain 16. Hemophilic females are rarer than hemophilic males. Explain why? 17. Why are vectors with single recognition sites preferred for cloning 18. Meat diet creates more demand for cereals. Explain. or Give two characteristics of energy transfer in ocean ecosystems. Section C 19. Draw a labeled diagram of the structure of a mammalian ovum 20. What is the significance of Competitive Exclusion Principle? Explain resource partitioning with reference to the above. 21 What are the 3 major steps in decomposition in nature? 22. What did Thomas Morgan experiment with? What was the importance of his discovery? Explain. 23. What are Bioreactors? How is it suitable for its use? 24. What is the basis of Homology of organs? Give examples from plants and animals. 25. Explain how ABO blood grouping is an example for multiple Alleles 26. What technique can be used to produce poultry with increased homozygozity? What are the advantages of the technique? State one disadvantage? 27. What is altitude sickness? What is the cause ?How is it overcome or Describe Primary succession on a bare rock Section D 28. What are the salient features of the Lac operon? OR What is regulation of gene expression? Explain how gene expression is regulated at different levels? 29. How are transgenic animals useful to man? OR What are cloning vectors? What are the features required to facilitate cloning in a vector? 30.Explain how microbes are useful, commercially? Or What is the basis of vaccination? How are vaccines prepared? What is passive immunization? When is it given? Give Eg. Answer Key 1. A test cross is used to determine genotype of dominant phenotype 1/by crossing with its recessive parent. 1/2+1/2=1 2. Excessive growth of planktonic algae/due to large amounts of nutrients in water bodies ½+1/2=1 3. Allergy. 1 4. Adaptive radiation. 1 5. Through contaminated food and water 1 6. Introduction of alien species – nile perch caused rapid extinction of nature fish variety 1 7. Spectral quality of light at different depths differ. 1 8. Earthworm causes fragmentation – catabolism is hence faster 1 9. It is formed from thalamus. true fruits develop from the ovary. 2 10. Ref:fig 2.5 a 11. Male flowers/female flowers Male gamete/female gamete. 12. Zygote----->morula----> Blastula-----> Blastocyst 2 Blastulation 13. lysozyme/chitinase 14. Gross primary productivity-total energy used for photosynthesis. NPP=GPP-Respiration 15. Leading strand-- continuous in 3’--->5’ direction lagging strand--- okazaki fragments formed discontinuously 16 Heamophilia is sex linked/recessive gene –show cross. 2 17. To prevent formation of several fragments/easier. -multiple sites will complicate cloning . 18. Each trophic level receives less energy then the previous level to get 1kg of meat, herbivore should be given at least 3-5 kg of cereals or Unidirectional /loss of energy at every stage of transfer 19. Ref.Ref:fig3.10. 20. One superior species eliminate the inferior / species have evolved mechanism/ to prevent overlap of feeding time /space and thereby prevent competition. 21. Decomposition; Fragmentation-breaking into pieces by detritivores/ leeching of minerals./ Catabolism, breakdown by enzymes of bacteria. 22. (i) not subjected to frequent disturbances. (ii) less seasonal environmental change (iii) more productivity 23.Drosphila melanogaster. Evidence for chromosome theory of inheritance and linkage / dihybrid crosses In Drosphila to study sex –linked genes/ greater number of parental combination were obtained than new combinations. 24. Large volumes of culture can be processed vessels/ in which raw materials are biologically converted into specific products individual enzymes /provides optimal condition for achieving the desired product by proving optimum growth conditions. 25 .Divergent evolution/{any one}each ./thorn and tendrils of Bougainvillea and cucurbit/ brain of vertebrates. 26. Three alleles of gene I-IA,IB,i A A I I IA i -A group B B B I I -I i B group IA IB AB group ii -O group More than 3 alleles governing blood group 27.Inbreeding /to breed pure lines /inbreeding depression 28.Nausea ,palpitations at high altitudes/ less oxygen due to low pressure/ increase RBC production or Bare rock-- lichens-- bryophytes-- bigger plants--- traces/ climax community/.lichens degrade soil with enzymes 29. fig 6.14.-Promoter- /operator/structural genes/lactose is inducer/ removes repressor molecule from operator/ or To study genes and the regulation of their expression Regulation of protein formation /at transcriptional level/splicing/transport of mRNA to cytoplasm /at the translational level 30. To study effect of genes on normal physiology and development/ study of disease through models of transgenics/to produce useful biological products/testing vaccine safety/to test toxicity of drugs or Plasmids, bacteriophages Origin of replication-sequence where replication starts Selectable marker; to identify and eliminate non transformants/ and peremit the growth of transformants eg antibiotic resistance coding gene 28.1. Bio gas production/.fermented beverages/.vaccines/.antibiotics/.bio-enzymes (any 5) or Memory cells of immune system Antigenic proteins/inactivated pathogen Preformed antibodies given to individuals Against snake venom To avoid delay in immune reaction . MODEL QUESTION PAPER (UNSOLVED) - 3 Time allowed : 3 Hrs. Max. Marks: 70 General Instructions: (i) This question paper contains four sections A,B,C and D. a. Section A contains of 5 questions of 1 mark each. b. Section B contains of 10 questions of 2 mark each. c. Section C contains of 10 questions of 3 mark each. d. Section D contains of 3 questions of 5 mark each. (ii) All questions are compulsory. (iii) Draw the diagram wherever necessary and label it. Section A 5X1=5 Answer the questions in one word / one sentence. 1. What is emasculation? 2. Name the biological term on transfer of Pollen grains from the anther to stigma of another flower of the same plant. 3. Write the medical term on a foetal sex determination test based on the chromosomal pattern in the amniotic fluid surrounding the developing embryo. 4. Name the gene responsible for the disease sickle cell anemia 5. Expand the term ELISA. 6. Define regeneration 7. What is locus? 8. Which epoch is called "age of mammals and angiosperms"? Section B 10 X 2 = 20 9. Explain the following a. Eutrophication b. Biological magnification 10. What is net primary productivity? 11. What is commensalism? Site and example. 12. Compare and contrast the two advantages and disadvantages of production of genetically modified crops. 13. What is gene gun method? Or Differentiate benign tumors and malignant tumors 14. Name the Causative organisms of the following diseases. c. Malignant malaria d. Ring worms e. Filariasis f. Pneumonia 15. Draw the structure of a mature spermatozoan and label the parts. 16. Name the type of evolution present in thorns and tendrils of Bougainvillea and cucurbita site another example among animals. 17. If the sequence of one strand of DNA is written as follows. 5’ –A T G C A U C A G T A C C A G C T – 3 Write down the sequence of complementary strand in 5’ – 3’ direction. 18. Why is Human Genome project called a mega project? Section C 10 X 3 = 30 19. What is incomplete dominance? With suitable example explain it. 20. With a neat labeled diagram, describe the structure of a typical angiosperm ovule. 21. Briefly explain the lac operon concept studied by Jacob and Monod. 22. Explain the Urey and Miller’s experiment. 23. Enlist the harmful effects caused by alcohol and drug abuse. What steps would be taken to prevent it from teen age children? 24. Write the various steps involved in DNA finger printing. Mention any three advantages. or Draw the structure of an antibody molecule and describe the same. 25. What are chromosomal disorders? Explain the following disorders. g. Down’s Syndrome h. Kline felter’s syndrome i. Turner’s Syndrome. 26.Suggest some methods to assist infertile couples to have children. 27. Write the functions of the following j. Corpus luteum k. Endometrium l. Acrosome m. Sperm tail n. Fimbriae o. Colostrum Section D 3 X 5 = 15 28. Briefly explain the difference between spermatogenesis and Oogenesis. Or Recently invasion of forest into Arctic region has been reported by environmentalist; which was earlier occupied by Tundra Vegetation. Identify this problem and explain its causes. 29. To prove that DNA is a genetic material by Fredrick Griffth 1928” – in transformation method. Or What is Bt toxin? Name the organism that produces it? How has it been exploited. Enlist the microbes that are used as bio fertilizers and write the functions. 30. What measures as an educated individual, you would take to reduce environmental pollution? Or Give an account of energy flow in an ecosystem. SAMPLE PAPER(UN SOLVED) - 4 Time : 3 Hours Max.Marks : 70 General Instructions xv. xvi. xvii. xviii. xix. xx. xxi. This Question paper consists of four sections, A,B,C and D. Section A contains 5 questions of one mark each , Section B is of 10 Questions of two marks each Section C is of 10 questions of three marks each and Section D is of 3 Questions of five marks each. All questions are Compulsory There is no overall choice. However, an internal choice has been provided in one question of 2 Marks, one Question of 3 marks and all three questions of 5 Marks. You have to attempt only one of the choices in such questions. Question number 1 to 5 are to be answered in one word or in one sentence each Question number 6 to 15 are to be answered in approximately 20 – 30 words each. Question number 16 to 25 are to be answered in approximately 30 – 50 words each. Question number 26 to 28 are to be answered in approximately 80 – 120 words each. Section A 1. What is embryogenesis? 2. What is colostrum? 3. Name one primary and secondary lymphoid organs? 4. Which symbiotic nitrogen fixing cyanobacterium lives in association with azolla? 5. What types of relation ship exists between sea anemone and hermit crab? Section B 6. Name the reproductive structure of the following 1. Penicillium 2. Sponges 7. How do back cross and Test cross differ? 8. Why Mendal selected pea plant for his experiment? Or How does DNA express Its biological information? 9. Draw a schematic structure of a transcription unit? 10. how does CO interfere with Oxygen transport in the blood? 11. Why hardening is essential for establishment of plantlets in the fields? 12. With the basic steps involved in genetically modified organisms? 13. What are transgenic plants? 14. List some techniques used for the purpose of early diagnosis of diseases? 15. What is a blubber? Section C 16. Explain the process of double fertilization? 17. Write short notes on Multiple alleles? 18. What do you understand by a leading strand and a lagging strand during DNA replication? 19. Life originated in the sea water. Support this statement. 20. Explain the role of innate immunity in protection from infectious agents? 21. Briefly describe the role of symbiotic nitrogen fixing bacteria in the improvement of soil fertility. 22. Write the major steps involved in down stream processing? 23. Write notes on Bt cotton? 24. Give the ecological adaptations of succulents? 25. What is biosphere? What are the main sub divisions of the biosphere? Or What are the causes of the bio diversity losses? Section D 26. Describe the structure of a mature anther with a neat labelled diagrams Or Explain the female reproductive system with a labelled sketch 27. Give a brief account of protein synthesis Or What is aneuploidy? Write short notes on the following 1. Down’s syndrome 2. Klinefelters syndrome 3. Turners syndrome 28. Define the following terms with one example each 1. Predation 2. Competition 3. Parasitism 4. Commensalism 5. Mutualism Or What are the different ways to control pollution. Explain the different ways of removing the particulate matter.? MODEL QUESTION PAPER (UNSOLVED) – 5 Class XII Marks : 70 Time: 3 hrs Section A 1. Name the disorder in which 45 autosomes with XO condition is seen. Mention any one characteristic feature of it. (1) 2. Define amensalism 3. Expand VNTR Why is it so called? 4. What is apiculture? 5. Name the pathogen that causes filariasis 6. What is infertility? 7. Clones are said to be carbon copy of parent. why? 8. Name the technique by which female to foeticides is carried out. Section – B 9. What is the purpose of doing test cross? Why is homozygous dominant parent not used? 10. Draw a neatly labeled diagram of matured embryo sac of a flowering 11. plant? How do the plants adapt themselves for preventing auto gamy and geitonogomy? 12. Write any two adaptations of xerophytes. 13. Name the immunity in which body attacks self – cells. Give an example (OR) Differentiate inbreeding from out breeding 14. Differentiate upright and inverted pyramids. 15. Name the enzyme essential for transcription to occur. What is the direction through which transcription occurs? 16. Using a Punnet square, work out the distribution of phenotypic features in first filial generation after a cross between a homozygous female and a heterozygous male for a single locus. 17. Write down the role of gel electrophoresis and restriction endonuclease. 18. List out any one advantage and disadvantage of GM crops. Section C 19. What is adaptive adaptive radiation? Explain with suitable example 20. What are "cry" proteins? Name an organism that produces it. How has man exploited this protein? Name an organism that produces it. How has man exploited this protein to is benefit? 21. Explain briefly the important features of a sedimentary cycle in an ecosystem. 22. What is gene therapy? Illustrate using an example of adenosine deaminase (ADA) deficiency (OR) Briefly mention any three vectors and their role for cloning genes in plants and animals. 21. Mention any three goals of HGP . 22. The following is the sequence of nucleotides in mRNA . AUG UUU UUC UAA UUU UUC . a. Find out the corresponding sequence . b. Name the aminoacid represented by first codon in mRNA . c. In which direction does transcription of mRNA occur 23. List any three important Characteristics of population and explain it . 24. Discuss the causes and effects of global warming. What measures need to be taken to control global warming? 25. List out any three microbes and their role in the production of enzymes . Section D 26. Draw the schematic diagram that shows the stages in the life cycle of Plasmodium .How many hosts it requires to complete its cycle . OR Enumerate the steps involved in plant breeding . 27. Explain the development of human sperm through spermatogenesis . OR Explain the development of female gamete through megasporogenesis in plants. 28. Explain origin of life with Miller's experiment . OR Explain LAC Operon concept . CONTRIBUTION OF SOME SCIENTISTS SCIENTIST 1. Gregor John Mendel 2. Betteson and Punnette CONTRIBUTION  Laws of heredity  Father of modern Genetics  Complementary genes in Lathyrus 3. T.H.Morgan  Sex linked Inheritance in Drosophila 4. Johannsen  Coined the term "Gene" 5. C.B.Bridge  Non-disjunction in chromosome 6. D. Iwanovsky  Discovered virus 7. Watson & Crick  Double Helical model of DNA 8. Avery; Me Leod, Me carty  9. Beadle & Tatum  DNA is the basis of hereditary characters One-gene-one enzyme hypothesis 10. Nirenberg  Genetic code 11. Jacob & Monod  Operon concept 12. Robert & Shap  13. Karl Landsteiner  Discovered exon and intron in Eukaryotes. ABO Blood 14. Sutton & Boveri  Chromosomal of inheritance 15. F.Griffth  Bacterial Transformation 16. Hershey & Chase  Bacterial Transduction 17. Messelson & Stahl  Semi conservative of DNA 18. Robert Briggs  Discovered once genes 19. Archibald Garrod  “In born errors of metabolism” Alkaptonuria.

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