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Reproduction in higher organisms Plants Angiosperms Are Flowering plants like rose, magnolia Have covered seeds.They protect the seed. Gymnosperms Are seed plants like pine(conifers) Have naked or uncovered seeds. Plants Angiosperms Gymnosperms Reproduction in flowering plants Gametes are formed in reproductive organs. Anther and ovary The gametes which are formed by meiosis, undergo mitosis. Meiosis mitosis Plant embryos are protected and fed in seeds. Pollen transport is specialized. Wind, water, insects. Diploid (2n)stage is developed. Pollination and Fertilization events are different. Flower structure The female part is the pistil. The pistil usually is located in the center of the flower and is made up of of three parts: the stigma, style, and ovary. The stigma is the sticky knob at the top of the pistil. It is attached to the long, tubelike structure called the style. The style leads to the ovary which contains the female egg cells called ovules. The male parts are called stamens and usually surround the pistil. The stamen is made up of two parts: the anther and filament. The anther produces pollen (male reproductive cells). The filament holds the anther up. Flower structure If a flower holds male and female reproductive organs it is a full flower(perfect). Tomato, apple, cherry If a flower has only one of the reproductive organs, it is imperfect(unisexual) flower. If an individual plant is either male or female the species is regarded as dioecious. Poplar(Kavak), salix(söğüt), fig (incir) However, where unisexual male and female flowers appear on the same plant, the species is considered monoecious. Pine(Çam), corn (mısır), walnut(ceviz), hazelnut(fındık) Self pollination Fertilization Pollination is the landing of pollens on stigma. Self pollination Cross pollination After pollination a tube grows down the style and enters the ovary The generative nucleus divides into 2 by mitosis and form 2 sperm cells. One of the sperm cells unites with egg to form zygote(2n) or embryo. The other sperm cell unites with polar nuclei(2n) and form endosperm(3n) Double fertilization in angiosperms. Formation of female gamete Formation of male gamete Anther 4 Pollen sac Ovary Ovule (tohumtaslağı) Polen mother cell (2n) Megaspore mother cell (2n) Meiosis Meiosis Microspore(n) (4 Cells) 4 Megaspores (n) Mitosis vv gg vv gg 3 disappear, 1 stays alive Pollen(çiçek tozu) (n)(4 cells) (vegetative nucleus(tüp), generative nucleus) 1 Megaspore(n) Mitosis 3 Mitosis 2 Sperm cells (n)(8 sperms) Embryo sac ( 8 nucleus n) Egg 2 synergits 2 polars 3 antipods Formation of male gamete in Angiosperms Pollen mother cells(microspore mother cell) (2n) undergoes meiosis in pollen sac and forms 4 microspores(n). Microspres undergo mitosis and forme pollen with 2 nuclei. (vegetative and generative nucleus) Vegetative nucleus forms pollen tube when it lands on stigma during pollination. Generative nucleus divides by mitosis and form 3 sperm cells. Formation of female gametes Megaspore mother cell(2n) in the ovule undergo meiosis and form 4 megaspores.(macrospres) 3 of the megaspores die and one lives. 1 megaspore undergo 3 mitosis and forms embryo sac with 8 nuclei. 1 is egg cell, 2 synergid cells support egg, 3 antipod cells and 2 polar nuclei. Double Fertilization in Angiosperms: 1 (n) of the two sperm cells fertilizes egg (n) and form the zygote(2n) than the embryo. The other sperm cell fertilizes polar nuclei(2n) and form a triploid (3n) structure. Fertilization and pollination in Angiosperms(protected seed plants) Gymnosperms- Pine Seed is not covered. So seed is naked. Usually male and female organs are on the same plant but in different parts. There is only one fertilization. Embryo is 2n, endosperm is n They pollinate by wind. Pollination and fertilization in gymnosperms(naked seed plant) Seed and fruit Zygote 3n(triploid)cell Ovule Ovary Embryo 2n Endosperm- food supply(3n) Seed and seed coat(testa)(2n) Fruit (2n) A fruit is a ripened ovary *exocarp: outer skin *mesocarp: fleshy to fibrous middle *endocarp: stony or bony "pit" *coconut, olive, peach, cherry, apricot, almond, avocado, etc.. aggregate fruit A fruit that develops from a single flower with several to many pistils (ie. carpels are not fused into a single pistil) *tissue not associated with ovary (such as the receptacle) contributes to accessory fruit formation Meyve sadece dişi organın yumurtalık dokuları tarafından meydana getirilirse bunlara gerçek meyve denir. Örneğin; şeftali, kayısı, üzüm. Yumurtalıkla birlikte çiçek tablası, taç ve çenek yapraklar beraberce gelişerek meyve oluşturuluyorsa bunlara yalancı meyve denir. Örneğin; Çilek, elma, armut. Bir tane dişi organdan meydana gelen meyvelere basit meyve denir. Örneğin; Kiraz, erik, elma. Birkaç tane dişi organdan meydana gelen meyvelere ise bileşik meyve denir. Örneğin; Ahududu, böğürtlen. Ceviz, fındık, kestane gibi bitkilerin meyveleri zamanla sertleşip kurur. Tohumları yenilen bu meyvelere kuru meyve denir. REPRODUCTION IN ANIMALS In animals gametes are formed only by meiosis. Gametes fertilizes and form the zygote or embryo. Fertil,ization can be inside or outside of the body. External fertilization is seen in fishes, molluscs, frogs. SSperm and egg unites in water and zygote develops in water. Internal fertilization occurs inside of the female animal. This process enables easy fertilization . Male animal transfers the gametes/sperms) to the genital tract of the female. Sperms are in a liquid inwhich they can move easily and find female gamete (egg) and fertilizes it. Unfertilized aggs are thrown out of the body and useless. Sharks, dolphin, whale, humans Internal and external fertilization It is difficult to find and fertilize the egg in external fertilization. The development of the zygote and embryo is very difficult in external fertilization. The gamete number should be large to maintain the fertilization. Which of them is common in all internal fertilization types? I. The egg number is reduced than the external fertilization II. Development of the Reproductive organs encourage fertilization. III. The possibility of the fertilization of the egg is very low. a. Only I b. Only II d. I and II c. Only III e. I, II and III Internal fertilization in birds Egg types and properties Eggs are different according to their vitellus amount. According to the egg type the developmental type is diffrent in animals. The vitellus amount is more in animals with external fertizitaion and external development than the animals with internal fertilization and internal development. The animals with external fertilization and external development don’t have protective layers of amnion, chorion and waste storing allantois. The vitellus amount is more in animals with internal fertilization and external development. These animals have protective layers of amnion, chorion . Their waste storing part allantois also gets bigger during the development of the embryo. The animals with internal fertilization and internal development don’t have so much vitellus. Because the exchange food with placenta. Amnion and chorion is well developed. Allantois is very small and doesn’t grow. Because they also exchange waste material by placenta with mother. Reproduction in humans The fertilization occurs inside of the body and embryo develops inside of the mother. Formation of egg in humans Meiosis occurs in ovaries. But the meiosis in humans is unequal division. Ony one oocyte is big and can live and be fertilized. Oocyte develops with follicle cells aroud it. Follicle cells protects and nourishes the egg. Only one follicle with one egg gets mature in one month. Every month one egg is thrown out(ovulated) from the ovary. The ovulated oocyte enters fallopian tube. The fertilization happens in the fallopian tube. After fertilization zygote forms and begins mitotic divisions. The fertilized egg travels down the fallopian tube and reaches uterus where it binds and develops. Formation of Sperms in humans Spermatogenesis Spermiogenesis Sperm formation occurs in seminiferous tubules of testis. Spern mother cells(spermatogonia) undergoes meiosis. But these cells have cytoplasmic bridges. These cytoplasmic bridges enables simultaneous maturation of sperm cells. Sperms taht are formed at the end of the meiosis don’t have the mobility, they undergo some changes. They lose their excess cytoplasm and produce flagella to move. Most of the mobility is gained in epididymis. The entire process takes 100 days. Anterior pituitary FSH- Growth of follicle, secretion of estrogen LH- Ovulation Ovary secretes: Estrogen- thickening of uterus Progesteron- thickening of uterus Corpus luteum: The follicle cells stayeing in ovary after ovulation forms corpus luteum. Secretes estrogen and progesteron. Main stages in female menstrual cycle Follicle stage: Follicle with egg cell develops in the ovary (during 5-14 days) (FSH, estrogen) Ovulation stage: Egg is thrown out to fallopian tube.(during 14-15 days)(LH, estrogen) Corpus Luteum stage: the cells in the ovary produces hormones. These hormones prepare uterus for a possible fertilization. (15-28 days) (progesteron,estrogen) Menstruation stage: If there is no fertilization, hormones decrease and endometrium is thrown out from the body. (0-5 days) (FSH) Ovulation stage Follicle stage Corpus Luteum stage Menstruation stage Hormonal control of female reproductive system Hypothalamus Releasing Factor Ant. Pit. Follicle stimulating hormone FSH Ovary Development of follicle Luteinizing hormone LH Ovulation Folikül Corpus luteum Estrogen Progesteron Thickening of endometrium Development of repr. organs Preparation to pregnancy Feedback LTH- Luteotropic hormone acts on mammary gland Hormonal control of male reproductive system Hypothalamus Releasing factor RF Ant. Hypophysis FSH LH Spermatogenesis Testis Seminiferous tubules Testosteron Hormone production Androgen Spermatogenesis Male properties Fertilization Fertilization Fertilization happens after ovulation in fallopian tubes. Sperm cells penetrate to the cell membrane of the egg and acrosome vesicle help penetration. It has hydrolytic enzymes. Only sperm nucleus enters egg. When it enters nuclei of gametes unite and form 2n zygote. Embryo forms from zygote with mitotic divisions. Zygote undergo mitosis during its journey to the uterus. There it binds to the endometrium (implantation). SPECIES African elephant ADULT MASS/kg GESTATION PERIOD/weeks 6000,0 88,0 Horse 400,0 48,0 Grizzly Bear 400,0 30,0 Lion 200,0 17,0 Wolf 34,0 9,0 Badger 12,0 8,0 Rabbit 2,0 4,5 Squirrel 0,5 3,5 http://www.saburchill.com/chapters/chap0038.html Development in plants Dicotyledones Monocotyledones Germination Seeds have very low water content. They have to take in water to facilitate reactions(enzyme activity). Seeds take in water and swell. Testa(seed coat) bursts. Enzymes become active. Amylase breaks down starch into glucose and use them in cellular respiration. Proteases breakdown proteins in the endosperm. Molecules are used in the growth of the embryo until photosynthesis. Wet weight a-b : seed is inactive e B-c: germination begins, absorbs water f C-d: seed uses food stores abc d time D-e: plant starts photosynthesis and produces new cells E-f : plant flowers, and dies Seed structure Seeds contain an embryo plant. Radicle: will form root Plumule: will form shoot Cotyledones: store food. Testa: protects embryo. Monocotyledones(tek çenekli) The first leaf is single. Seed is whole (one part) Leaves are double veined Petals are 3 or multiples of 3 Vascular bundles are not regularly arranged. Dicotyledones(çift çenekli) The first leaf is double. Seed has 2 parts. Leaves are net veined Petals are 4 or 5 Vascular bundles are regularly arranged in circle. Factors affecting plant development Environmental conditions: temperature light Soil Water Gases Gravity Nitrogen and carbohydrates Biotic factors Hormones Encouraging development Auxin Gibberellin Cytokinin Stopping development Abscisic acid Ethylene Development in animals An organism starts its journey as 1 cell(zygote) and become an ornism with millons of different cells. The processes which make them many and different are as follows: Cell division(segmentation): Zygote divides by mitosis. Growth: The increase in mass by feeding and division. Differentiation: Cells differentiate to form different kinds of cells by gene activation. Nature or nurture http://history1900s.about.com/od/auschwitz/a/mengeletwins_ 2.htm http://www.wordwiseweb.com/AUSCHWITZ/AUSCHWITZ/ twins.html http://www.dusunenadam.com/2004/2004_06_07.html http://www.ists.qimr.edu.au/ * http://www.washingtonpost.com/wpdyn/content/article/2005/07/04/AR2005070400845.html http://www.sciencenews.org/articles/20050709/fob1.asp http://www.niehs.nih.gov/research/clinical/program/groups/g eigroup.cfm http://www.libraryindex.com/pages/2233/GeneticsEnvironment-TWIN-STUDIES.html Extraembryonic Membranes Extraembryonic membranes functions in protection, feeding and development of the organism.Birds, mammals, reptiles have extraembryonic membranes. Amnion memb:It is filled with amnion fluid. Protects embryo and prevents drying. Vitellus memb: It is attached to the digestive system. It has egg yolk to feed the developing embryo Allantois memb: It is attached to the digestive system(last part). It stores wastes. Chorion: Protects embryo and other membranes(structures). It also helps for gas exchange with allantois. Development of a bird embryo General rules for embryonic development 1. 2. 3. Division: The number of the cells increase. But the volume of the cells decrease. The total volume equals to the zygote. Gastrulation: Cell diffrentiation starts. 3 embryonic layers are formed. Endoderm, ectoderm, mesoderm. Organogenesis: Development of organs Developmental stages 1. Division The cells formed by mitotic divisions are called as blastomeres. When they look like berry they are called as morula. The cells push each other and form a space inside and this space is known as blastocoel. This stage is called as blastula. Each cell in blastula have the capacity to form a new indiviual. During division number of the cells increases but their volume decreases. 2. Gastrulation After blastula cells begin to differentiate and move. Embryonic layers are formed. These layers will form the systems of the body. In gastrula cells form a permanent space inside. This space later will form the digestive tract of the organism. During gastrulation cell layers effect each other. In that way differentiation speeds up. This differention with the effect of other cell layers is called as induction(uyarılma). If the tissues from a layer is transplanted to anoy-ther place, they can develop into a different organ. Spemann is the scientist who investigated this phenomena . Embryonic Induction Cell differentiation and formation of the organs are the results of the gene activation. The interactions between cells effect the gene activation. The interaction between Mesoderm and ectoderm, will cause the development of vertebrae from mesoderm and neural tube from ectoderm. During the formation of eye, neural ectoderm and head ectoderm interact. The relative position of particular cell layers helps determine the organs that develop. • Inducer cells produce a protein factor that binds to the cells of the target tissue, initiating changes in gene expression. • Development is a process of progressive restriction of gene expression. • At the stage called commitment, every cell's fate becomes fixed. 1. He took out the upper ectoderm of the embryo and put the dissected part into the tissue culture. Embryo without upper ectoderm developed into a full embryo without neural tube but the ectoderm didn’t developed into neural tube. He thought that ectoderm needs another cell layer to differentiate into neural cord. He cut the upper ectoderm open and took out the mesoderm below it. Then he closed the ectoderm again. He observed that neural cord didn’t form from the ectoderm. He thought that mesoderm has a role on ectoderm for neural tube differentiation. Spemann used 2 embryos in this experiment. He took out the mesoderm below the ectoderm from one of the embryos and transplanted it to the mesoderm of the second embryo(to a different part). First embryo didn’t form a neural tube, but second embryo formed 2 neural tubes (one is normal one, the other is the transplanted one) He thought that mesoderm should effect the ectoderm of the embryo fort he formation of the neural tube. Eye development Eye is formed with the induction of neural and head ectoderm. Neural ectoderm form the eye cup(retina) and the head ectoderm will form the lens and cornea of the eye. Neural tube formation 3. Organogenesis The development of organs and tissues from the embryonic layers is known as organogenesis. Gene activation, movement of cells, embryonic induction are the reasons for organogenesis. DNA is same in each cell but different genes are active, so they differentiate into different cells and organs. Ectoderm Mesoderm Endoderm Skin ectoderm Neural ectoderm muscle digestion skin brain blood Pancreas Nail, hair Spinal cord skeleton Liver Nerves, sense organs urinary Lung reproductiv e Throid mucosa, bladder http://www.visembryo.com/baby/in dex.html Development of a human embryo Protection and feeding of embryo Placenta develops after the implantation of the embryo. The blood vessels of mother and child are very close to each other. Embryo feeds from the maternal blood. Umblical cord has 2 arteries and 1 vein. Placenta also functions as an endocrine organ, secretes estrogen and progesteron. Birth http://www.me d.upenn.edu/m eded/public/be rp/overview.mo v http://www.ms nbc.com/modul es/fetal_stages/ FETUS.swf Multiple birth There are two common types of multiple births, fraternal (dizygotic) and identical (monozygotic). Identical siblings arise where one egg is fertilized and the resulting zygote splits into more than one embryo. Identical siblings therefore have the same genetic material. Fraternal siblings result from the fertilisation and implantation of more than one egg. Yandaki şemada omurgalı bir canlı türüne ait bazı hücreler numaralandırılmıştır. Buna göre şemada numaralandırılmış hücrelerle ilgili olarak hangi ifade doğru değildir? A. I ve II hücreler farklı genetik yapıdadır. B. III ve IV hücreler mayoz ile oluşmuştur C. I ve II hücrelerindeki genlerin tümü V hücreye aktarılır D. V. hücre mitoz geçirir E. V hücredeki homolog kromozomların yarısı III, yarısı IV den gelmiştir. Aşağıdaki olaylardan hangisi sonucunda oluşan hücre ana hücreden farklıdır? a. b. c. d. e. Kayısı bitkisinde makrospordan oluşan megaspor hücresi Kertenkelenin I. Oositinden oluşan II. Oosit hücresi Papatyada generatif çekirdekten oluşan sperm çekirdekleri Eğrelti otunun gametofitinden oluşan yumurta hücresi İnsan zigotundan oluşan 2 blastomer hücresi Aşağıda verilenlerden hangisi çevresel değişmenin etkisi ile oluşan modifikasyona örnektir? a. b. c. d. e. Bazı deniz canlılarının korunmak amacı ile deniz kumunun renginde olması Göçmen kuşların kışı sıcak bölgelerde geçirmesi Paramesyumun bölünerek çoğalması sonucu oluşan hücrelerin farklı büyüklükte olması Kokarcanın düşmanına karşı koku salgılaması Hayvan türlerinin uygun mevsimlerde yavrulaması Tüp bebek http://www.abc.net.au/science/lcs/ivf.htm http://biotechadventure.okstate.edu/low/teacher/basics