Reproduction 10th biology for 10th1-1.pptx

For 10th grade students

1. By: Tajamul Islam Khan How do Organisms Reproduce? 1

2. Reproduction Living organisms produce new individuals of their own kind and maintain their existence generation after generation. This process is called as Reproduction. Importance of Reproduction: Continuation of life on Earth To maintain the size of the population Transfer of variation from one generation to another. 2

3. Reproduction – Basic Steps DNA in the cell nucleus is the information centre for making protein The first step in reproduction is replication of DNA followed by cell division. Variations happen during copying of DNA. These variations are the basis of evolution . Variations are useful for the survival of species over time. 3

4. Importance of DNA copying in Reproduction DNA Copying: Organisms pass on their characteristics to their offspring. Importance of DNA Copying: Maintains characteristics in different generations. DNA is the blueprint and it ensures correct body design. Any change in it causes change in synthesis of proteins and in turn body design. i.e. it will cause variation. 4

5. Variation is Beneficial for the Species Variation – Change in body design of an individual It allows organisms to adapt and exist in diverse habitat or niches. Small variations or variations over time, will help the species in its survival in different conditions. However, drastic variation in a single individual will affect its chance of survival. It is the basis of evolution. 5

6. Types of Reproduction There are two types of reproduction namely (a) Asexual reproduction and (b) Sexual reproduction Asexual Reproduction Sexual Reproduction New individual is produced from a Single parent New individual is produced from two parents It does not involve union of gametes Involves union of gametes. Younger ones are genetically identical to the parents Younger ones are not genetically identical to the parents Variations are absent Variations are present 6

7. Various Types of Asexual Reproduction Types of Asexual Reproduction Fission Budding Fragmentation Regeneration Vegetative Propagation Spore Formation 7

8. Fission Fission is a process of division of single celled organism into two or many cells. Binary Fission : Fission into two cells . Takes place during favorable conditions. E.g. Amoeba, Paramecium Multiple Fission : Fission into many cells. Takes place during unfavorable conditions. E.g. Plasmodium (which causes Malaria) 8

9. Budding Budding is a method of reproduction in which a protuberance develops on the mature organism’s body, attains full maturity and detaches. E.g. Hydra, Yeast 9

10. Fragmentation Fragmentation is a process in which body of an individual simply breaks up into smaller pieces upon maturation. These pieces or fragments grow into new individuals . E.g. Spirogyra 10

11. Regeneration Regeneration is the ability of an organism to replace or repair any lost part . Carried out by specialized cells. E.g. Planaria, Hydra 11

12. Differences between Fragmentation and Regeneration 12

13. Spore Formation Spores are special cells formed within special structures called ‘sporangia’. Sporangia disseminate and can form the entire plant This is exclusive to plant kingdom E.g. Aspergillus, Fungi-Rhizopus, Mushroom 13

14. Vegetative Propagation Vegetative Propagation is a method of reproduction where a vegetative plant part produces a new plant. Here vegetative part refers to non-reproductive or non-flowering part of the plant body such as Stem, root, leaves. e.g. Bryophyllum , Rose, Jasmine, Sugarcane, 14

15. Natural Vegetative Propagation 15

16. Artificial Vegetative Propagation Artificial Vegetative propagation is done through cutting, Layering and Grafting. Cutting - e.g. Grapes, Bougainvillea, cactus, Pineapple 16

17. Artificial Vegetative Propagation Mound Layering – made to grow as an independent plant and plant can be cut from main plant Layering 17

18. Artificial Vegetative Propagation Grafting Joining a part of one plant with other Root Stock Supporting and Rooted part (disease resistant) Scion Cutting from a desirable plant (superior quality) Cambium of Scion is in direct contact with cambium of stock New Plant with Root System of Stock + Shoot system of Scion 18

19. Importance of Vegetative Propagation 19

20. Sexual Reproduction Sexual Reproduction involves male and female individuals to produce new organism. It involves the formation and fusion of male and female gametes. New individuals exhibit variation , it helps in the processes of adaptation. Cell division involves meiosis. 20

21. Importance of Sexual Reproduction Variations ensure retaining of a species with in the community. As DNA of two individual organisms of same species are involved, sexual reproduction results in variation. Sexual reproduction helps in crossing over and it is essential for variation. Variation allows organisms to live in diverse habitat with the help of adaptation. During this type of reproduction fusion of gametes take place. This helps to maintain constant number of chromosomes throughout the species. 21

22. Plant Reproductive System Flower is the reproductive part of the plant. Male reproductive part is Stamens. Female reproductive part is Carpel. 22

23. Unisexual flowers : The flower that has only male or female reproductive part present are unisexual flowers. Examples of unisexual flowers  are Bitter gourd ,  papaya, pumpkin, cucumber, maize. Bisexual flower: The flower possessing both male and female reproductive part is called a bisexual flower. Also called hermaphrodite flower. Examples: Rose, Sunflower, Tomato, Mustard, Brinjal . 23

24. Male reproductive part in Plants Parts of Stamen 24

25. Female reproductive part in Plants Parts of Carpel 25

26. Pollination Pollination: Transfer of pollen grains from anther to stigma by agents like wind, water and insects etc. Two types of pollination – Self Pollination Cross pollination 26

27. Types of Pollination Self Pollination: Transfer of pollen grains from anther to stigma of same flower . Cross Pollination: Transfer of pollen grains from anther to stigma of different flower of same plant or different plant. Flower to Flower Pollination Type A → A Self A → B Cross A → C Cross B → C Cross 27

28. Various methods (Agents) of cross pollination are:   Entamophily : Pollination by insects. Ex. rose, sunflower Anemophily: Pollination by wind. Ex. Maize, walnut Hydrophily : Pollination by water. Ex. Vallesneria Zoophily : Pollination by animals. Ex. Figs Ornithophily : Pollination by birds. Ex. brush, red coral tree.

29. Fertilisation in Plants Fertilisation It is the process of fusion of male gametes (male germ cells) and female gametes (female germ cells or egg cells). 29

30. Fertilisation in Plants 30

31. Formation of Seed Formation of Seed 31

32. Human Reproductive System Puberty : Reproductive system of young organisms become functional at a definite age. At puberty, 32

33. Importance of Hormones Regulates the process of gametogenesis (formation of gametes) Maintains structure and function of accessory sex organs Develops secondary sexual characteristics such as facial, axial and pubic hair, change pitch of voice development of mammary glands. 33

34. Male Reproductive System . Ureter Urinary Bladder Urethra Pair of Testis (inside pouch like muscular structure – Scrotum) Vas Deferens Prostate Gland Seminal Vesicle 34

35. Functions of Male Reproductive System Sperms are produced in Testis Requires temperature 1 or 3 º less than body temperature To maintain less temperature Testis are present in Scrotum – a muscular pouch like structure Sperms enter urethra through Vas Deferens – a long tube like structure Just before sperms enter urethra, Sperms are enriched with secretions from Prostrate gland and Seminal Vesicle To provide nutrition and motility for Sperms Urethra opens outside to genital pore. Urethra is enclosed in muscular organ - Penis Urethra and Genital pore are common for both Urine and Sperms 35

36. Female Reproductive System . Pair of Ovaries Funnel like structure leading to Fallopian Tube Uterus Cervix 36

37. Functions of Female Reproductive System Pair of Ovaries produce Ova Secretes two hormones Estrogen and Progesterone Composed of follicles that produce Ova at puberty Uterus At end of ovary, funnel like structure leads to Fallopian tube. Fallopian tubes from both ends open into elastic bag like structure - Uterus Cervix Uterus opens into vagina through the cervix Vagina has a tubular structure. Starts producing Ova at puberty Vagina is the birth canal through which the young ones are born. Urethra and Vaginal openings are separate. 37

38. Sexual Cycle in Females  If fertilisation doesn’t occur, uterine lining along with blood vessels break down.  Broken down Uterline lining moves out of body.  Ovarian follicles Mature into Egg or Ovum  Released from respective Ovary.  Uterine wall starts to thicken  Ovum waits for fertilisation to occur.  Further thickening of Uterine wall happens. 38

39. Fertilization 39

40. Fertilization in humans 40

41. Functions of Placenta Special tissues called placenta forms between Uterine wall and foetus . Placenta provides nutrition to the developing embryo. Helps in the exchange of CO 2 and oxygen . Helps in the removal of waste substance formed in the developing foetus . Development of foetus takes about 9 months. Birth of foetus occurs through rhythmic contraction of muscles in the uterus. 41

42. Population Control 42

43. Reproductive Health Reproductive health includes aspects such as Responsible, safe and satisfying reproductive life. Awareness regarding fertility regulation methods , the right, freedom and choice to control birth. Ability to prevent and control sexually transmitted diseases. Sexually Transmitted diseases (STDs): Infectious diseases caused by pathogens such as bacteria, protozoans virus and fungi that spread through sexual contact. e.g . Gonorrhoea ( Nesseria gonorrhea) , Syphilis ( Treppnema , Trichomoniasis, AIDS etc. Most STDs causes symptom such as burning sensation in urination and urethral discharge. AIDS (Acquired Immuno Deficiency Syndrome) is caused by HIV (Human Immuno Deficiency Virus). Its cure has not been found till now and it may cause death if not treated properly. 43

44. Thank you 44