Gametogenesis: spermatogenesis and oogenesis
- Consider the following :A. The reductive division for the human female gametogenesis starts earlier than that of the male gametogenesis.B. The gap between the first meiotic division and the second meiotic division is much shorter for males compared t… Answer: 1. A and B are true Key idea: Compare timing of meiosis in the two sexes and the role of hormones. A is true. In females meiosis I b... 1
- Match List - I with List - II.List - I: A. Head; B. Middle piece; C. Acrosome; D. TailList - II: I. Enzymes; II. Sperm motility; III. Energy; IV. Genetic materialChoose the correct answer from the options given below : Answer: 1. A-IV, B-III, C-I, D-II Head: genetic material (IV) Middle piece: mitochondria give energy (III) Acrosome: enzymes for penetrating... 1
- Identify the correct option (A), (B), (C), (D) with respect to spermatogenesis.[Flow chart: GnRH -> LH -> (B) -> Androgens -> Formation of spermatids; GnRH -> (A) -> (C) -> Factors -> (D)] Answer: 2. FSH, Leydig cells, Sertoli cells, spermiogenesis. Key idea: in males, LH acts on Leydig cells to make androgens, and FSH acts on... 1
- Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R :Assertion A : FSH acts upon ovarian follicles in female and Leydig cells in male.Reason R : Growing ovarian follicles secrete estrogen in female wh… Answer: 1. A is false but R is true Key idea: check the target cells of FSH. In females FSH acts on ovarian follicles. In males FSH acts on... 1
- Which of the following statements are true for spermatogenesis but do not hold true for Oogenesis ?(a) It results in the formation of haploid gametes(b) Differentiation of gamete occurs after the completion of meiosis(c) Meiosis occurs continuously i… Answer: 1. (b), (c) and (e) only Key idea: Compare each statement for the two processes. (a) Both give haploid gametes. Not exclusive. (b) I... 1
- Given below are two statements :Statement I :The release of sperms into the seminiferous tubules is called spermiation.Statement II :Spermiogenesis is the process of formation of sperms from spermatogonia.In the light of the above statements, choose… Answer: 4. Statement I is correct but Statement II is incorrect Key idea: Spermiation and spermiogenesis are different steps. Statement I: s... 1
- At which stage of life the oogenesis process is initiated ? Answer: 3. Embryonic development stage Key idea: Oogenesis begins before birth, during the embryonic stage. Oogonia form in the foetal ovary... 1
- Extrusion of second polar body from egg nucleus occurs : Answer: 1. after entry of sperm but before fertilization Key idea: Sperm entry stimulates completion of meiosis II. The secondary oocyte is... 1
- The difference between spermiogenesis and spermiation is Answer: 4. In spermiogenesis spermatozoa are formed, while in spermiation spermatozoa are released from sertoli cells into the cavity of sem... 1