* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 8 How Do Organisms Reproduce
Survey
Document related concepts
Plant defense against herbivory wikipedia , lookup
Plant secondary metabolism wikipedia , lookup
History of botany wikipedia , lookup
Plant breeding wikipedia , lookup
Plant physiology wikipedia , lookup
Ornamental bulbous plant wikipedia , lookup
Plant ecology wikipedia , lookup
Plant evolutionary developmental biology wikipedia , lookup
Plant morphology wikipedia , lookup
Perovskia atriplicifolia wikipedia , lookup
Pollination wikipedia , lookup
Fertilisation wikipedia , lookup
Flowering plant wikipedia , lookup
Transcript
Assignments in Science Class X (Term II) 8 How Do Organisms Reproduce IMPORTANT NOTES 1. In asexual reproduction, certain body cells undergo repeated mitotic divisions and give rise to two or more new organisms of the same kind. 2. Different methods of asexual reproduction are — fission, budding, fragmentation, spore formation, regeneration, vegetative propagation, parthenogenesis and tissue culture. 3. Fission is a process of division of a single celled organism into two or many cells (called binary and multiple fission respectively), e.g., Amoeba. 4. Budding is a method of reproduction in which a protuberance develops on the mother organism’s body, attains full maturity and then detaches, e.g., Yeast or Hydra. S ER TH O R B 5. Spore formation : Spores are the special cells formed within special structures called ‘sporangia’ that disseminate and can form the entire plant. This is exclusive to the plant kingdom, e.g., mushroom/ferns/mosses. Vegetative part 1. Leaf 2. Root 3. Stem 4. Vegetative buds called bulbil N A SH A K A PR 8. Advantages of Vegetative Propagation (i) It allows quicker and easy propagation. (ii) Better qualities of the plants can be maintained and the quality can even be enhanced as in seedless oranges. (iii) It results in propagation of those plants which do not produce viable seeds or produce seeds with prolonged period of dormancy. 9. Disadvantages of Vegetative Propagation Most of these propagated plants do not produce viable seeds and hence curtail natural reproduction. 10. Regeneration is the ability of an organism to replace or repair any lost part. Sometimes, an entire organism can be made from its fragmented body, e.g., Planaria. When an unfertilised egg can be made to develop into an entire organism, it is known as ‘Parthenogenesis’ in animals and ‘Parthenocarpy’ in plants. 11. The reproductive part of a plant is its flower. A complete flower has four whorls —sepals, petals, androecium and gynoecium. 6. Vegetative propagation is a method of reproduction in which a vegetative plant part (i.e., a non-reproductive part or a nonflowering part) produces a new plant. L YA O G is buried under the soil for a while, till it strikes new roots. It is then detached from the mother plant, e.g., Jasmine. This is called ‘soil layering’. The other form of layering is ‘air layering’ in which incision is made on the bark of a tree and covered with moist soil. When rooting takes place in the cut portion, the entire portion is cut and used for propagation. (iii) Grafting is a process in which two parts of different plants are joined by bandaging them tightly. This allows cambial activity to unite the two portions. The one that contributes the root is called ‘stock’ and the one that contributes the shoot is known as ‘scion’. Bicoloured roses/different varieties of mangoes are made by this method. Example Bryophyllum/Kalanchoe Mint/Seasam Rose/Mango Agave 7. For artificial propagation by man, the commonly used methods are : (i) Cutting in which a stem is given an oblique cut and the cut stem is kept under appropriate conditions to give rise to an entirely new plant, e.g., Rose / China rose. (ii) Layering is a process in which the stem, while still attached to the mother plant 1 12. Male gametes are the pollen grains produced by the anther lobes and the female gametes are the ova within ovules present inside ovaries. (iii) (iv) (v) (vi) 13. The transfer of pollen grains from the anther to the stigma is known as pollination. Vas deferens Urethra Penis Accessory glands (seminal vesicle and prostrate gland) 21. Female reproductive system in humans consists of the following organs — (i) Ovaries (ii) Fallopian tubes or oviducts (iii) Uterus or womb (iv) Vagina 22. The gonads control and regulate three major functions : 14. After pollination, pollens get deposited on the stigma. The pollen germinates by forming pollen tubes. Each tube carries two male nuclei at its tip. (b) They help in the functioning of the accessory sex organs (i.e., organs which are a part of the reproductive system but do not directly produce gametes). 15. The ovary bears ovules. The number of ovules vary from one (as in mango) to many (as in orchid). Each ovule contains an embryo sac which has a haploid egg and two other haploid nuclei which fuse to form a polar nucleus. S ER TH O R B 16. During syngamy, the first male nucleus fuses with the ovum to form the zygote. The second male nucleus fuses with the polar nucleus to form the endosperm. 18. In most animals single individual produces only one type of gametes and hence is unisexual. However, there are organisms that possess both testicles and ovaries and are called bisexuals or hermaphrodites, e.g., earthworm and leech. (a) Vas deferens (b) Urethra is a common passage for the release of urine as well as sperms. Testicles function throughout the life of a man, from puberty onwards, though the quality of the sperms declines with age. 24. The attainment of sexual maturity is known as puberty. The female puberty is considered to be attained with the first menstrual discharge and this is called ‘Menarche’. The stoppage of menstruation marks the end of the reproductive life in females and is known as ‘Menopause’. 19. The fusion of the two gametes is known as ‘fertilisation’: Fertilisation Internal (within the body of the female e.g., birds/human) (c) They help in the development of secondary sex characters like breast development in girls and growth of facial hair in boys. 23. In male the testicles are lodged in the scrotum outside the body as the process of sperm formation requires a temperature lower than the normal body temperature. The other parts of this system are : 17. The entire process is summarised as “double fertilisation” and ‘triple fusion’. The fertilised ovule develops into a seed and the fertilised ovary into a fruit. L YA O G N A SH A K A PR (a) Produce the gametes as well as the sex hormones (testosterone is produced by the testicles and estrogen and progesterone by the ovaries). External (In the medium like water outside the female body e.g., frog/fish) 25. Population control involves measures by which fertilisation is prevented. The three common methods are : 20. Male reproductive system in human consists of the following organs — (i) Testes in the scrotum (ii) Epididymis (a) Physical barrier methods like condoms or placing of IUCDs (Intra Uterine Contraceptive Devices) in the uterus of the female. 2 (b) Chemical methods like use of oral or vaginal pills. (c) Surgical methods which involves a surgery in which the tubes conducting the gametes are cut and tied. It is known as vasectomy in males and tubectomy in females. healthy ones during sexual contacts. Gonorrhoea and syphilis are common STDs. AIDS (Acquired Immuno Deficiency Syndrome) is also transmitted by sexual contact. Responsible sexual behaviour and prudence can help to prevent the spread of STDs. Both government (National Population Policy and National Health Policy) and nongovernment organisations are endeavouring to control the fertility rate. 26. STDs are sexually transmitted diseases, also called veneral diseases (VDs). They are transmitted from the infected individuals to I. VERY SHORT ANSWER QUESTIONS N A SH A K A PR (1 Mark) A. IMPORTANT QUESTIONS 12. Which parts of the flower transform into the seed and fruit? 13. Which group of plants shows double [HOTS] fertilisation? 14. What is the function of pollen grains in flowers? 15. Where is the zygote located in the flower after [HOTS] fertilisation? 16. What are gonads? 17. What is external fertilisation? 18. What is internal fertilisation? 19. What is semen? 20. Where are the ova produced in woman? 21. What are oral contraceptives? 22. What is epididymis? What is the function of epididymis? 23. What are the functions of urethra? 24. What are the secondary sexual characters in human male? 25. When does puberty occur in human male and female? 1. What is a spore? 2. Name two plants which reproduce through spores. 3. Why is regeneration considered a method of reproduction? 4. Which vegetative part is used in the propagation of bryophyllum and mint? S ER TH O R B 5. Name two types of layering. 6. Which technique would you use for propagating improved varieties of mango and rose? 7. Mention one physiological advantage of grafting quality roses on wild rose stock. L YA O G [HOTS] 8. Give two examples of organisms, which can regenerate from small part of their body. 9. Name the plant whose intact leaves produce plantlets along the margin. 10. What is the main difference between stem cutting and layering? 11. Which process results in zygote? B. QUESTIONS FROM CBSE EXAMINATION PAPERS 1. Name the type of fission carried out by Amoeba. [2009] 5. List two functions performed by ovaries in a human female. [2006] 6. Write the full form of IUCD. [2005] 7. Write the full expansion of HIV. [2005] 8. Name any two sexually transmitted diseases. 2. Why is DNA copying an essential part of the process of reproduction? [2009] 3. What is the effect of DNA copying which is not perfectly accurate on the reproduction process? [2008] [2004] 9. List the general characteristics of the pollen grains of wind-pollinated plants. [2000] 4. Write the expanded form of AIDS. [2006, 2005] 3 II. SHORT ANSWER QUESTIONS–I (2 Marks) A. IMPORTANT QUESTIONS 1. Suggest two reproduction. advantages of 9. What are the advantages of tissue culture? asexual [HOTS] 10. In tobacco plant, the male gametes have twenty-four chromosomes. What is the number of chromosomes in the female gamete? What is the number of chromosomes in the zygote? 2. When and how does multiple fission take place? 3. Some crop plants can be grown from a seed as well as vegetatively from stem cutting. List any four advantages of vegetative propagation in such cases. [HOTS] [HOTS] 11. Why cannot fertilisation take place in flowers [HOTS] if pollination does not occur? 4. “Grafting is a common method of obtaining a superior plant from two different plants”. Explain. 12. Give two reasons for the appearance of variations among the progeny formed by sexual reproduction. [HOTS] 5. Colonies of yeast fail to multiply in water, but multiply in sugar solution. Give one reason for this. [HOTS] N A SH A K A PR 13. In a bisexual flower inspite of the young stamens being removed artificially, the flower produces fruit. Provide a suitable explanation for the above situation. [HOTS] 6. Can you consider cell division as a type of reproduction in unicellular organism? Give one reason? [HOTS] 14. What are the changes seen in girls at the time of puberty? 7. Why does bread mould grow profusely on a moist slice of bread rather than on a dry slice of bread? [HOTS] 15. What changes are observed in the uterus if [HOTS] fertilisation does not occur? S ER TH O R B 16. What are the benefits of using mechanical barriers during sexual act? [HOTS] 8. Draw a diagram of longitudinal section of a pistil showing pollen germination and label the following parts. (i) style (ii) pollen tube [HOTS] 17. Explain how, offspring and parents of organisms reproducing sexually have the same number of chromosomes? [HOTS] B. QUESTIONS FROM CBSE EXAMINATION PAPERS L YA O G 1. What is placenta? State its any two roles during [2011 (T-II)] pregnancy. 2. State in brief any two functions of copper-T [2011 (T-II)] used by some women. 3. In what respect is the human male gamete different from the female gamete? 7. Name the type of asexual reproduction in : (a) Planaria (b) Rhizopus (c) Spirogyra (d) Hydra [2011 (T-II)] 8. (a) Surgical methods can be used to create a block in the reproductive system for contraceptive purposes. Name such parts where blocks are created in : (i) Males (ii) Females (b) State any two reasons for using [2011 (T-II)] contraceptive devices. 9. (a) What is vegetative propagation? (b) Write any two advantages of practising [2011 (T-II)] this method. 10. How does the process of budding differ from the process of spore formation? [2011 (T-II)] 11. (a) Out of the following plants which two plants are reproduced by vegetative propagation? jasmine, wheat, mustard, banana [2011 (T-II)] 4. What will happen when : (a) A mature Spirogyra filament attains considerable length? (b) Planaria gets cut into two pieces? [2011 (T-II)] 5. (a) Give reason : Regeneration is not the same as Reproduction. (b) State the mode of a sexual reproduction [2011 (T-II)] in Plasmodium 6. State in brief the role of the prostate gland and seminal vesicles in the male reproductive [2011 (T-II)] system? 4 (b) List any one advantage of practising this [2011 (T-II)] kind of propagation. 12. List any two reasons for adopting contraceptive [2011 (T-II)] methods. 13. (a) Why do testes located in scrotum outside the abdominal cavity? (b) What will happen to ovary and ovule after fertilization in angiospermic plants. 20. With the help of a diagram only show regeneration in Planaria. Regeneration is not possible in all types of animals. Why? [2011 (T-II)] 21. How does the process of seed germination take place in plants? Describe in brief. [2011 (T-II)] 22. How do sexual and asexual reproduction lead to speciation? Give one point for each. [2011 (T-II)] [2011 (T-II)] 14. (a) Name two animals which reproduce asexually? (b) What are the male and female gonads in human beings known as? [2011 (T-II)] 15. State the significance of human testis being [2011 (T-II)] located in the scrotum? 16. The organisms formed by asexual reproduction are considered as clones. Why? State the advantage of sexual reproduction over asexual [2011 (T-II)] reproduction. 17. (a) What is the site of implantation and development of young one in human female? (b) Mention two advantages of using mechanical barriers during sexual act. 23. Name the sex hormones secreted by male and female sex organs in human beings. State one [2011 (T-II)] function of each. 24. State the mode of reproduction in following organisms : Earthworm, Frog, Rhizopus, Plasmodium. [2011 (T-II)] 25. What are sexually transmitted diseases? Name an STD which damages the immune system of human body? [2011 (T-II), 2009] 26. What is reproduction? What are its two types? Which one of the two confers new characteristics of the offspring and how? S ER TH O R B [2009] 27. What is binary fission? Draw a diagram to show binary fission in Amoeba. [2009] 28. What is regeneration? State a reason why a more complex organism cannot give rise to new individuals through this method. [2009] 29. Name the male and female gametes in animals. What is fertilisation and where does it take place in human females? [2009] 30. Name one sexually transmitted disease each caused due to bacterial infection and viral infection. How can these be prevented? [2008] 31. Name any two sexually transmitted diseases. What advice is given to prevent them? [2008] 32. What methods will you use for growing jasmine and rose plant? [2004] 33. Describe how the sex of the offspring is determined in the zygote in human beings. [2011 (T-II)] 18. (a) Leaves of Bryophyllum fallen on the ground produce new plants whereas the leaves of jasmine do not. Why? (b) Write two points of differences between asexual and sexual reproduction. [2011 (T-II)] 19. In a bisexual flower inspite of the young stamens being removed artificially, the flower produces fruit. Give reasons. (a) Name the parts of the flower which ripens to form fruit and seed? (b) In the following diagram label A and B. L YA O G N A SH A K A PR [2011 (T-II)] [2004] III. SHORT ANSWER QUESTIONS–II (3 Marks) A. IMPORTANT QUESTIONS 1. Differentiate between binary fission and multiple fission. 2. Can an unfertilised egg form a new organism in the sexually reproducing type of organism? 5 10. Mention the important post-fertilisation [HOTS] changes in a flower. 11. What is a seed? How does it help in [HOTS] reproduction in plants? 12. What are the advantages of sexual reproduction over asexual reproduction? 13. If a woman is using a copper-T, will it help in protecting her from sexually transmitted [HOTS] diseases? 14. How are the modes of reproduction different in unicellular and multicellular organisms? 15. Mention the methods used for regulation of child birth. 16. Describe the surgical method of birth control. 17. Differentiate between menarche and menopause. 18. Why is it said that “sexual reproduction promotes diversity of characters in the [HOTS] offsprings”? 19. What would be the ratio of chromosome number between an egg and its zygote? How is the sperm genetically different from the egg? Describe the two terms associated with the same. [HOTS] 3. Justify that parthenogenesis is not the same as asexual reproduction. 4. What criteria and precautions should be taken into consideration while selecting stock and [HOTS] scion? 5. With the help of a neat sketch illustrate any three natural methods of vegetative propagation. 6. Only through labelled diagrammatic representation, represent the process of budding as seen in Hydra. 7. How are general growth and sexual maturation [HOTS] different from each other? 8. Draw a diagram to illustrate fertilisation in a flowering plant and label the following on it (a) Pollen grains (b) Egg 9. Draw a labelled diagram of the longitudinal section of a flower. S ER TH O R B N A SH A K A PR B. QUESTIONS FROM CBSE EXAMINATION PAPERS 1. In a sexually reproducing plant, what happens to zygote formed after fertilization? State in brief. [2011 (T-II)] (b) What happens in case the eggs released by the ovary is not fertilized? 2. State in brief the function of the following organs in the human female reproductive system: (a) Ovary (b) Fallopian tube (c) Uterus [2011 (T-II)] 6. (a) Draw a neat diagram of longitudinal section of an ovule to show fertilization of pollen on stigma and label the following parts: 3. (a) Identify the asexual method of reproduction in each of the following organisms : (i) rose (ii) yeast (iii) planaria (iii) Ovary (iv) Female germ cell (b) Give any two advantages of vegetative propagation. [2011 (T-II)] 7. In the diagram of human male reproductive system given below : L YA O G [2011 (T-II)] (i) Pollen Tube (ii) Stigma (b) What is fragmentation? Name a multicellular organism which reproduces by this method. [2011 (T-II)] 4. State the role of father and mother in the determination of sex of new born child. Support your answer with a suitable illustration. [2011 (T-II)] 5. (a) How many eggs are produced every month by either of the ovaries in a human female? Where does fertilization take place in the female reproductive system? 6 (i) Vas deferens (iii) Prostate gland (a) Label parts A and B. (ii) Testis [2011 (T-II)] (b) Name the hormone produced by organ ‘X’. What is the role of this hormone in the human male? 13. (a) Name an organism in which binary fission occurs in a definite orientation. (c) Mention the name of substances that are transported by tubes (b) Draw a neat diagram of a germinating seed and label on it the following : (i) C (ii) D [2011 (T-II)] 8. Differentiate between : (a) Asexual and sexual reproduction. (b) Plumule and Radicle (c) Pollination and Fertilization [2011 (T-II)] Cotyledon, Plumule, Radicle [2011 (T-II)] 14. (a) Name the parts 1 to 5 of human female reproductive system. (b) Name the part in which fertilization takes [2011 (T-II)] place in the system. 9. (a) Why is vegetative propagation practised for growing some types of plants? (b) Name the different parts of a flower that has germ cells. (c) List any two agents of pollination. [2011 (T-II)] 10. (a) What is the difference between self pollination and cross pollination? (b) What happens to the pollen which falls on a suitable stigma? Explain. 15. (a) How do the oral pills function as contraceptives? [2011 (T-II)] S ER TH O R B 11. Name the parts A, B and C shown in the given diagram and state one function of each part. [2011 (T-II)] L YA O G N A SH A K A PR (b) The use of these pills may be harmful. [2011 (T-II)] Why? 16. List and describe in brief any three ways [2011 (T-II)] devised to avoid pregnancy. 17. (a) Draw a neat diagram of female reproductive system in human being and label on it : (i) the part which secretes ova. (ii) the part where implantation takes place. (b) What happens if the fallopian tube is blocked? [2011 (T-II)] 12. State one function of each of the following parts of human male reproductive system. 18. Study the given data and answer the questions that follow : 1 Parental plant cross fertilized and seeds collected 2 F1 Generation offspring 3 F2 Generation offspring after self pollination of F1 hybrid Male parent - Round Green seeds Female parent - Wrinked Yellow seeds All seeds - Round Yellow 314- Round Yellow 110- Round Green 102- Wrinkled Yellow 32- Wrinkled Green 7 (a) What is the term given to this type of cross? 25. What is vegetative propagation? When is it used? Name three methods of vegetative [2006] propagation. (b) What does the data in column 2 indicates? 26. (i) Which are the two main types of reproduction in living organisms? State how did you arrive at this [2011 (T-II)] conclusion. (ii) Classify the following under these two types: 19. (a) Explain the terms : (i) implantation (ii) placenta Amoeba, Frog, Earthworm, Yeast. [2006] 27. What are the male and female gonads in human beings? State any two functions of each [2006] of them. (b) What is the average duration of human [2009] pregnancy? 20. Illustrate the following with the help of suitable diagrams : 28. Define any three of the following terms used in relation to human reproduction : (i) Fertilisation (ii) Implantation (iii) Placenta (iv) Gestation [2005] (v) Parturition (i) Binary fission in Amoeba (ii) Leaf of Bryophyllum with buds. [2008] 21. Illustrate the following with the help of suitable diagrams : N A SH A K A PR 29. (i) When does ovulation occur during the menstrual cycle in a normal healthy female? (i) Spore formation in Rhizopus. (ii) Multiple fission in Plasmodium. [2008] (ii) Draw a labelled diagram to show the reproductive system of a human female. 22. Differentiate between ‘self-pollination’ and ‘cross-pollination’. Describe ‘double [2004, 2007] fertilisation’ in plants. [2004] 23. (i) What is fertilisation? Distinguish between external fertilisation and internal fertilisation. 30. Name any two Sexually Transmitted Diseases (STDs). How do these infectious diseases spread from one person to another? Give two [2004] symptoms of STDs. (ii) What is the site of fertilisation in human [2007] beings? 24. Define the terms unisexual and bisexual giving [2007] one example of each. 31. Draw a diagram of a flower to show its male and female reproductive parts. Label on it : (a) The ovary (b) The anther (c) The filament (d) The stigma [2004] S ER TH O R B IV. LONG ANSWER QUESTIONS L YA O G (5 Marks) A. IMPORTANT QUESTIONS 1. Define the term layering. What are its two types? How is one different from the other? 8. How is tissue culture technique performed? In which area this technique is finding its application? 2. Tabulate the process of reproduction into its various types, giving one example of each type. 9. Why does menstruation occur? 3. How are ornamental plants grown artificially? [HOTS] 10. What are the factors responsible for the sharp increase in population? 4. With a set of suitable diagrams, describe the process of budding as seen in yeast. 11. What do you know about reproductive health of human beings? 5. Reproduction is essentially a phenomenon that is not for survival of an individual but for the stability of a species. Justify. [HOTS] 6. Draw and write about the structure of an ovule. 12. With the help of a diagram, describe how fertilisation takes place in female reproductive [HOTS] system. 7. Explain double fertilisation with the help of a diagram. 13. Distinguish between a gamete and zygote. Explain their roles in sexual reproduction. [HOTS] 8 B. QUESTIONS FROM CBSE EXAMINATION PAPERS 1. (a) What is the role of seminal vesicles and the prostate gland? (b) What are the three categories of contraception methods? Write briefly [2011 (T-II)] about each. parts of the human female reproductive system. (i) Ovary (ii) Fallopian Tube [2011 (T-II)] (iii) Uterus 6. (a) Differentiate between germination and fertilization. (b) State in brief the functions of the following parts of the human male reproductive system: (i) Scrotum (ii) Testes [2011 (T-II)] (iii) Vas deferens 2. (a) Draw longitudinal section of a flower and label on it the following : (i) Ovary (ii) Style (iii) Stigma (iv) Anther Why is vegetative propagation practised for growing some plants? Give two examples of plants grown by this method. [2011 (T-II)] 3. (a) In the given figure name the parts marked 1 to 6 : S ER TH O R B (b) Differentiate between Pollination and Fertilization. [2011 (T-II)] L YA O G N A SH A K A PR 7. (a) Draw a neat diagram of the reproductive system of a human female and label on it the following : (i) reproductive part that produces the female hormone (ii) site of fertilization (iii) organ where growth and development of the embryo takes place. (b) How does the growing embryo meet with its nutritional requirements? (c) What happens if the ovum is not fertilized? (d) Mention a contraceptive method that can be used by the human female. [2011 (T-II)] 8. (a) Name the female reproductive part of a flower. Draw diagram of its longitudinal section depicting the process of fertilization of pollen on stigma and label on it the following: (i) male germ cell (ii) female germ cell (iii) ovary (b) What happens to the following parts after fertilization? (i) ovum (ii) ovary (iii) ovule (iv) sepals and petals 4. (a) In the given figure name the parts marked 1 to 6 : [2011 (T-II)] 9. (a) Draw a neat labelled diagram of pistil showing fertilization of pollen on stigma. (b) Give the functions of : (i) stigma (ii) ovary (c) State in brief the formation of seed in a [2011 (T-II)] flower. (b) Differentiate between self pollination and cross pollination. [2011 (T-II)] 5. (a) Differentiate between pollen grain and ovule. (b) State in brief functions of the following 9 10. (a) State any two changes seen in girls at the time of puberty. (b) How does the embryo get nourishment inside the mother’s body? State in brief. (c) List any two commonly adopted, [2011 (T-II)] contraceptive methods. 11. Draw a neat diagram of the human male reproductive system and label the parts performing the following function : 12. 13. 14. 15. 16. 17. (a) (a) Production of sperms (b) Gland which provides fluid (c) Provides low temperature for the formation of sperms (d) Common passage for sperms and urine Name a sexually transmitted disease and a method to avoid it. [2011 (T-II)] (a) State any two changes seen in boys at the time of puberty? (b) Define fertilization and implantation. (c) State the role of ovary and fallopian tube in human body. [2011 (T-II)] (a) What is placenta? Mention its role during pregnancy. (b) What will happen if the egg is not fertilized. (c) Collection of yeast fail to multiply in water, but multiply in sugar solution. Give [2011 (T-II)] one reason for this. (a) What is vegetative propagation? How is it advantageous? Give suitable example. (b) How will an organism be benefited if it reproduces through spores? (c) How is regeneration different from [2011 (T-II)] fragmentation? (a) Draw a diagram showing fertilisation in a flowering plant and label—stigma, male germ cell, pollen grain, egg. (b) List two advantages of vegetative [2011 (T-II)] propagation. (a) Name a plant in which vegetative propagation takes place by leaves. (b) Write the causal organism of the following diseases. (i) Warts (ii) Syphilis (c) Draw a neat diagram of reproductive system of human female and label the following parts : (i) the part which is responsible for L YA O G (b) N A SH A K A PR (c) 18. (a) S ER TH O R B providing shelter to the growing embryo. (ii) the part where fertilization takes place. (iii) the part in which ovum formation takes place. (iv) the part which is ligated to avoid [2011 (T-II)] fertilization. Which device prevents implantation by irritating the lining of uterus? What could be the possible reason for declining female to male sex ratio in our country. Suggest two measures to achieve 1:1 ratio. Name those parts of a flower which serve the same function as the following do in animals : (i) Testis (ii) Ovary (iii) Eggs (iv) Sperms [2011 (T-II)] List two reasons for the appearance of variations among the progeny formed by sexual reproductuon. (i) Name the parts marked “1” and “2” in the following diagram. (ii) How does 1 reach on the 2? (iii) What happens to the part marked 4 after fertilization is over? (iv) Mention the importance of the part [2011 (T-II)] “3”. (b) 19. (a) Which part of the Bryophyllum develops into a new plant? (b) List two basic differences between male and female germ cells? (c) State two functions performed by testis in [2011 (T-II)] human male. 20. (a) Draw the diagram of a flower to show its male and female reproductive parts. Label the following parts in it : 10 (i) Ovary (ii) Anther (iii) Filament (iv) Stigma (b) How does fusion of male and female gametes take place in plants? [2011 (T-II)] 27. (a) 21. What is placenta? Describe its structure. State its function in case of pregnant human female. (b) (b) [2011 (T-II)] (c) 22. Draw a neat diagram of human male reproductive system and label on it the following parts : 23. (a) (b) 24. (a) (b) (c) 25. (a) (b) (d) (i) Prostate gland (ii) Seminal vesicle (iii) Testis State the function of testis. [2011 (T-II)] Draw a neat diagram to show fertilization in a flower and label on it the following parts: (i) Stigma (ii) Pollen tube (iii) Ovary State the function of pollen tube. List in tabular form any two differences between a male gamete and a female [2011 (T-II)] gamete. With the help of diagram show asexual reproduction in Rhizopus. How is this method advantageous for Rhizopus? How is mode of reproduction in unicellular organisms differ from [2011 (T-II)] multicellular organisms? State two advantages of vegetative propagation. Name two plants in which it is practised. How does Hydra reproduce? Explain in brief with the help of a labelled diagram. L YA O G (e) N A SH A K A PR 28. (a) (b) (c) 29. (a) S ER TH O R B (iii) Vas deference (iv) Prostate glands State the reason why testes are located outside the abdominal cavity.[2011 (T-II)] Why do multicellular organisms, need to use more complex ways of reproduction? What is the advantage of reproducing through spores? How does variation lead to the survival of species overtime? Is fertilization possible without pollination? Mention any one difference between self [2011 (T-II)] and cross pollination. Draw a diagram showing germination of pollen on stigma of a flower. Label pollen grain, male germ-cells, pollen tube and female germ-cell in the above diagram. [2008] How is zygote formed? Explain the role of placenta in the development of human embryo. (b) Give example of two bacterial and two viral sexually transmitted diseases. Name the most effective contraceptive which prevents spread of such diseases. [2007] 30. (a) Draw a diagram illustrating fertilisation in a flowering plant and label on it : Pollen grain, Male germ cell, Female germ cell, Stigma. (b) Describe the process of fertilisation in [2005] plants. 31. Give two reasons for avoiding frequent pregnancies of women. Explain the following methods of contraception giving one example of each : (i) Barrier method (ii) Chemical method (iii) Surgical method [2004] [2011 (T-II)] 26. (a) Mention the role of following organs of human male reproductive system. (i) Testis (ii) Scrotum an aquatic plant like pistia, a few mature leaves of Bryophyllum with young adventitious buds. Procedure: (i) Take an old potato tuber and examine it carefully. (ii) You will observe ‘eyes’ or small spots on the potato tuber. These eyes are actually the nodes of the stem. A. Experiment 1. Objective : To study vegetative propagation in potato, an aquatic plant and Bryophyllum. Materials Required: A hand lens (magnifying lens), an old potato tuber, 11 2. Objective : (iii) With the help of a hand lens (magnifying lens), examine each eye. There will be a small adventitious bud in each eye. (iv) Observe the origin of shoots from the surface of the tuber. (v) Draw sketches of a tuber with shoots. To study and describe the parts of a flower and their role in several reproduction. Materials Required: Flowers of Petunia or China rose, charts of transverse sections of anther and ovary, permanent slides of the flowers chosen, dissecting microscope, beaker, forceps, needle, slides, razor blade and cover slips. Procedure: (i) Keep the floral twigs in a beaker containing water to prevent drying of flowers. Vegetative propagation by stem in potato tuber N A SH A K A PR (ii) Examine the position of flower on the twig. Determine whether it is axillary or terminal; solitary or an inflorescence. (vi) Observe an aquatic plant carefully. (vii) Observe the formation of a new plant and the region of attachment of both plants. (viii) Draw diagram of the aquatic plant depicting the exact origin of a young plant. (iii) Study the following character of the flower and record the features : (a) Pedicellate – Flower with stalk (pedicel) Sessile – Flower without stalk (pedicel) S ER TH O R B Vegetative propagation in an aquatic plant (ix) Observe the lamina of Bryophyllum leaf, particularly the leaf margins. (x) Plantlets will be seen arising some notches in the margin. (b) Complete Incomplete (c) Unisexual (xi) Draw a diagram of Bryophyllum leaf with plantlets attached to its margins. L YA O G Bisexual (d) Calyx Sepals Vegetative propagation in Bryophyllum leaf – Flower with all the four whorls sepals, petals, stamens and carpels. – Flower which lacks one or more floral whorls. – Flower with only one sex either stamen or carpel is present. – Flower with both stamens and carpels present in it (hermaphrodite). – Calyx is the outermost green whorl of floral leaves. Observe their colour and shape. – A leaf like division of calyx. Polysepalous – All the sepals are free. Gamosepalous– All the sepals are fused together. (e) Corolla – Corolla is the second, coloured whorl of the flower made up of petals; count the number Observations: (i) The surface of potato tuber has several eyes. (ii) New shoots arise from each eye. (iii) In aquatic plant, a new plant arises from the portion of parent plant. (iv) In Bryophyllum, plantlets develop from the margins of intact leaves. 12 of petals; observe their colour and shape. or more ovules attached to a flattened cellular cushion known as placenta. Polypetalous – Petals free from each other. Gamopetalous – Petals fused with each other. (f) Androecium – This is the third reproductive whorl in a flower made up of stamens. Mount one stamen on the stage of the dissecting microscope and observe its various parts such as a stalk (short or long) called the filament, and a terminal bilobed anther. (g) Gynoecium Parts of a flower – This is the innermost whorl of female reproductive organs made up of pistils. Mount the pistil on the stage of the dissecting microscope and observe its various parts such as the basal swollen portion (ovary), a style and a flattened tip, stigma. Inside the ovary are one L YA O G N A SH A K A PR (iv) Cut a cross section of the anther. Mount the section in a drop of water taken on a slide. Observe it under the dissecting microscope. Locate pollen grains in the slide and the cavities in anther called pollen sacs. (v) Cut a cross section of ovary, mount the section in a drop of water taken on a slide. Observe it under the dissecting microscope. Count the number of chambers (locules) and locate ovules. (vi) Draw diagram of a flower showing all the four whorls—sepal, petal, stamen and pistil. (vii) Observe the permanent slides of transverse sections of anther and ovary. Identify different parts using the charts provided. Draw their diagrams in your notebook. S ER TH O R B (a) Sepals (calyx); (b) Petals (corolla); (c) Stamens (Androecium); and (d) Pistil (Gynoecium) Observations: Inflorescence: It is solitary axillary. Androecium: Stamens 5, epipetalous, long filament of unequal length. Gynoecium: Bicarpellary, bilocular ovary with many ovules. Flower: The flower is bell-shaped, occurs in violet, white, pink and many other shades. It is pedicellate, complete and bisexual. B. Quiz 1. A lizard escapes from its enemies by breaking off its tail. What do you think, a new tail will grow after sometime or not? Give reason behind your answer. Calyx: Sepals 5, green, gamosepalous. Corolla: Petals 5, gamosepalous, coloured variable, pink, red, etc. 13 2. Look at the diagram and answer the following questions. (i) Which type of reproduction is shown in the diagram? (ii) Do the hereditary characteristics remain the same in organism C and E? Why? 3. Human population is increasing everyday, and the increase is to extent that the population doubles in about 35 years. Name the factors responsible for the sharp increase in human population. S ER TH O R B N A SH A K A PR 4. Look at the picture and answer the following questions: (a) Name the process showing in the picture. (b) Name the parts labelled as A, B, C and D. L YA O G (iv) Product of fusion between two polar nuclei and one male nucleus. (v) Fluid that contains secretions of accessary glands together with the sperms. (vi) A large oval shaped cell present in the nucellus of the ovule in plants. (vii) Period during which the foetus develops inside the uterus. (viii) Reproductive age when menstruation begins. C. Puzzles 1. Look across, up and down in the grid to find the answers of the following: (i) Stalk of an ovule. (ii) Stoppage of menstruation in woman. (iii) Central tissue of the ovule surrounded by integuments. 2. Unscramble the following and write down the names of ten such reproductive organs. Sort them as male and female reproductive organs. (i) ANGAVI : ............................ (ii) SERIVOA : ............................ (iii) SETEST : ............................ 14 (iv) (v) (vi) (vii) (viii) (ix) (x) RAHTURE SIPEN SDVAEREFNES YIMSDIPIDE CTUDIOV TUEUSR EURTRE : : : : : : : ............................ ............................ ............................ ............................ ............................ ............................ ........................... (b) Importance of pollen tube (c) Post fertilisation changes 2. Topic—‘Improved reproductive health of women in rural area’. (Hints–Discuss the following points.) (a) Intrauterine contraceptive devices (b) Oral contraceptive (c) Surgical method of family planning in women. D. Group Activities 1. Ask the students to prepare a chart showing the process of reproduction. They can compare the asexual and sexual reproduction. F. Debate 1. Disease free plants can be produced by tissue culture. 2. Embryo is the future plant. 3. Because of pressure from the parents, friends or society, early age marriages certainly take place in many areas particularly rural ones. 2. Think of the situations in which the word ‘reproductive health’ is used in our life. Note down the ways in which the reproductive health of a woman become poor. Give the precautions which should be taken to avoid getting poor reproductive health. G. Group Discussion 3. From the internet, gather information about the chromosome numbers of five animals and five plants. Correlate the number with the size of organism and answer the following questions : (a) Do larger organisms have more number of chromosomes/cells? (b) Can organism with fewer chromosomes reproduce more easily than organisms with more number of chromosomes? (c) More the number of chromosomes/cells greater the DNA content. Justify. E. Seminar L YA O G N A SH A K A PR 1. What happens when the egg is not fertilised? 2. Agents of pollination. S ER TH O R B H. Survey 1. The groups of students (5-6) can go to different hospitals where family planning methods are being taken. (a) Find out the numbers of people taking surgical precautions for family planning, everyday. (b) How many ladies use intrauterine contraceptive devices? (c) What is the rate of failure of contraception methods? 2. Visit a park and make a list of the various pollinating agents of different plants. 1. Topic—‘Fertilisation is a step between pollination and seed formation’. (Hints–Discuss the following points.) (a) Structure of pollen grain and ovule S.No. Name of plant Pollinating agent 1. ................................. ................................. 2. ................................. ................................. 3. ................................. ................................. 4. ................................. ................................. 5. ................................. ................................. 6. ................................. ................................. 15