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(Chapter- 3) (Human Reproduction), (Class - XII), Question 1:, Fill in the blanks:, (a) Humans reproduce, (asexually/sexually), (oviparous/viviparous/ovoviviparous), in humans. (external/internal), (b) Humans are, (c) Fertilization is, (d) Male and female gametes are, (e) Zygote is, (f) The process of release of the ovum from a mature follicle is, called, (diploid/haploid), (diploid/haploid), (g) Ovulation is induced by a hormone called the, (h) The fusion of the male and the female gametes is called, (i) Fertilization takes place in the, (j) The zygote divides to form, (k) The structure which provides vascular connection between the fetus and, which is implanted in uterus., uterus is called, Answer 1:, (a) Humans reproduce sexually., (b) Humans are viviparous., (c) Fertilization is internal in human., (d) Male and female gametes are haploid, (e) Zygote is diploid., (f) The process of release of the ovum from a mature follicle is called, ovulation., (g) Ovulation is induced by a hormone called the Iuteinizing hormone., (h) The fusion of the male and the female gametes is called fertilization., (i) Fertilization takes place in the fallopian tube., (j) The zygote divides to form blastocyst, which is fertilization implanted, in uterus., (k) The structure which provides vascular connection between the fetus and, uterus is called placenta., Scanned by CamScanner
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Question 2:, Draw a labeled diagram of male reproductive system., Answer 2:, Ureter, Urinary bladder, Seminal vesicle., Prostate, Vas deferens-, -Bulbourethral gland, Spermduct, Testis, penis, The male reproductive system, Question 3:, Draw a labeled diagram of female reproductive system., Answer 3:, Uterine cavity, Uterine fundus, Fallopian tube, Ovary, re Uterus, Endometrium, Fimbriae, Myometrium, Perimetrium, Cervix, Cervical canal, Vagina-, The female reproductive system, Question 4:, Write two major functions each of testis and ovary., Answer 4:, Functions of the Testis, > They produce male gametes called spermatozoa by the process of, spermatogenesis., The leydig cells of the seminiferous tubules secrete the male sex, hormone called testosterone. Testosterone aids the development of, secondary sex characteristics in males., Scanned by CamScanner
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Functions of the ovary, > They produce female gametes called ova by the process of oogenesis., > The growing Graffian follicles secrete the female sex hormone called, estrogen. Estrogen aids the development of secondary sex, characteristics in females., Question 5:, Describe the structure of a seminiferous tubule., Answer 5:, The production of sperms in the testes takes place in a highly coiled structure, called the seminiferous tubules. These tubules are located in the testicular, lobules. Each seminiferous tubule is lined by germinal epithelium. It is lined, on its inner side by two types of cells namely spermatogonia and sertoli cells, respectively. Spermatogonia are male germ cells which produce primary, spermatocytes by meiotic divisions. Primary spermatocytes undergo further, meiotic division to form secondary spermatocytes and finally, spermatids., Spermatids later metamorphoses into male gametes called spermatozoa., Sertoli cells are known as nurse cells of the testes as they provide, nourishment to the germ cells. There are large polygonal cells known as, interstitial cells or leydig cells just adjacent to seminiferous tubules. These, cells secrete the male hormone called testosterone., Interstitial cells, Spermatozoa, Sertoli cells, Spermatogonia, Transverse section of seminiferous tubules, Question 6:, What is spermatogenesis? Briefly describe the process of spermatogenesis., Answer 6:, Spermatogenesis is the process of the production of sperms from the, immature germ cells in males. It takes place in seminiferous tubules present, inside the testes. During spermatogenesis, a diploid spermatogonium (male, germ cell) increases its size to form a diploid primary spermatocyte. This, diploid primary spermatocyte undergoes first meiotic division (meiosis I),, Scanned by CamScanner
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Question 9:, Draw a labeled diagram of sperm., Answer 9:, Acrosome, Head, Nucleus, Centrioles, Midpiece, Mitochondria, Sperm cell, Question 10:, What are the major components of seminal plasma?, Answer 10:, Semen (produced in males) is composed of sperms and seminal plasma. The, major components of the seminal plasma in the male reproductive system, are mucus, spermatozoa, and various secretions of accessory glands. The, seminal plasma is rich in fructose, calcium, ascorbic acid, and certain, enzymes. It provides nourishment and protection to sperms., Question 11:, What are the major functions of male accessory ducts and glands?, Answer 11:, The male accessory ducts are vasa efferentia, epididymis, vas deferens, and, rete testis. They play an important role in the transport and temporary, storage of sperms. On the contrary, male accessory glands are seminal, vesicles, prostate glands, and bulbourethral glands. These glands secrete, fluids that lubricate the reproductive system and sperms. The sperms get, dispersed in the fluid which makes their transportation into the female body, easier. The fluid is rich in fructose, ascorbic acid, and certain enzymes. They, also provide nutrients and activate the sperm., Scanned by CamScanner
