Q.(क) Draw a diagramatic labelled sectional view of seminiferous tubule of human.
(ख) Describe the spermatogenesis process in human. OR What is double fertilisation? In which plants does it occur? Describe the changes that occur after double fertilisation.

Showing the 12 most recent of 13 on this concept.

1. CBSE 2026Set ANNUAL1 mark
   Q.Fill in the blank: Leydig cells, synthesise and secrete testicular hormone called as ______.

   ›Reveal solutionSolution

   Leydig (interstitial) cells located between the seminiferous tubules secrete testosterone, the main male sex hormone.

   Within the testis, the region outside the seminiferous tubules contains Leydig (interstitial) cells, which synthesise and secrete androgens, principally testosterone, under LH stimula …

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2. CBSE 2025Set X11 markMCQ
   Q.The process of transformation of spermatids into sperms is called

   (a) Spermatogenesis

   (b) Spermiogenesis

   (c) Spermiation

   (d) Oogenesis

   ›Reveal solutionSolution

   The transformation of spermatids into mature spermatozoa is called spermiogenesis.

   During spermatogenesis, spermatids are produced. The subsequent morphological transformation of these non-motile spermatids into motile spermatozoa (sperms) is termed spermiogenesis. Spermatogenesis is the whole process of sperm formation; spermiation is the release of sperms from the Sertoli cells into the …

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3. CBSE 2025Set F1 markMCQ
   Q.Sertoli cells are controlled by which of the following hormones?

   (a) LH

   (b) FSH

   (c) Prolactin

   (d) GH

   ›Reveal solutionSolution

   Sertoli (nurse) cells are stimulated by FSH from the anterior pituitary.

   In the male, the anterior pituitary secretes two gonadotropins. LH (Luteinising Hormone / ICSH) acts on the Leydig (interstitial) cells to stimulate secretion of testosterone (androgens). FSH (Follicle Stimulating Hormone) acts on the Sertoli cells located within the seminiferous tubules; these nurse cells then …

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4. CBSE 2025Set ANNUAL1 mark
   Q.Define spermiogenesis.

   ›Reveal solutionSolution

   Spermiogenesis is the final stage of spermatogenesis where spermatids differentiate structurally into functional sperm.

   After meiosis II produces haploid spermatids, these round, non-motile cells undergo a process of structural transformation called spermiogenesis, during which they develop a head (with an acrosome and condensed nucleus), a middle piece (packed with mitochondria for energy) and a tail (flagellum) for …

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5. CBSE 2025Set ANNUAL1 markMCQ
   Q.There are two statements marked as Assertion (A) and Reason (R). Mark your answer as per the code given below : Assertion (A): From one diploid primary spermatocyte, four haploid sperms are formed. Reason (R): A primary spermatocyte is large and diploid, it contains 46(2n) chromosomes

   (i) Both (A) and (R) are true and 'Reason' is the corrrect explanation of (A).

   (ii) Both (A) and (R) are true but 'Reason' is not the correct explanation of (A).

   (iii) (A) is true but (R) is false.

   (iv) Both (A) and (R) are false.

   ›Reveal solutionSolution

   Both statements are factually correct, but stating that the primary spermatocyte is diploid with 46 chromosomes does not, by itself, explain why exactly FOUR haploid sperm result — that comes from it undergoing two successive meiotic divisions.

   Assertion (A): A primary spermatocyte, which is diploid, gives rise to four haploid sperm — this is true. It first undergoes meiosis I (a reductional division) to form two haploid secondary spermatocytes, and each secondary spermatocyte then undergoes meiosis II (an equational division) to form two spermatids each — giving four spermatids in total, which differentiate (spermiogenesis) into four sperms.

   Reason (R): A primary spermatocyte is indeed large and diploid, containing 46 (2n) chromosomes — this is also true.

   …

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6. CBSE 2024Set A11 markMCQ
   Q.The secondary spermatocytes undergo the second meiotic division to produce four equal, haploid

   (a) Spermatogonium

   (b) Spermatids

   (c) Primary spermatocyte

   (d) Secondary spermatocyte

   ›Reveal solutionSolution

   Secondary spermatocytes complete the second meiotic division to form four haploid spermatids.

   During spermatogenesis, a diploid primary spermatocyte undergoes the first meiotic division to give two haploid secondary spermatocytes. Each secondary spermatocyte then undergoes the second meiotic division, …

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7. CBSE 2024Set ANNUAL1 markMCQ
   Q.LH acts on :

   (a) Leydig cells

   (b) Sertoli cells

   (c) Both (A) & (B)

   (d) Spermatogonia

   ›Reveal solutionSolution

   Luteinizing Hormone (LH) targets the Leydig (interstitial) cells of the testis.

   In the male, the anterior pituitary secretes LH, which acts on the Leydig cells (interstitial cells lying between the seminiferous tubules). LH stimulates these cells to synthesise and secrete androgens, mainly testosterone, which in turn regulates spermatogenesis and the development of secondary sexual ch …

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8. CBSE 2024Set ANNUAL1 markMCQ
   Q.During spermatogenesis, meiotic division results in the formation of spermatozoa from primary spermatocytes. The total number of meiotic divisions required to produce 400 spermatozoa will be :

   (a) 200

   (b) 300

   (c) 100

   (d) 50

   ›Reveal solutionSolution

   Each primary spermatocyte undergoes 2 meiotic divisions to give 4 spermatozoa, so producing 400 spermatozoa needs 300 total meiotic divisions.

   During spermatogenesis, a primary spermatocyte (diploid, 2n) first undergoes meiosis I to form two secondary spermatocytes (haploid, n). Each secondary spermatocyte then undergoes meiosis II to form two spermatids each, so one primary spermatocyte ultimately gives rise to 4 spermatids (which differentiate into 4 spermatozoa) through a total of 2 meiotic divisions (1 meiosis I + 2 meiosis II, i.e. 1 + 2 = 3 individual division events per primary spermatocyte if counted cell-by-cell: 1 meiosis I of the primary spermatocyte, and 2 separate meiosis II divisions of its two secondary spermatocytes).

   To produce 400 spermatozoa: …

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9. CBSE 2023Set ANNUAL1 mark
   Q.Write the name of one sex hormone secreted by human male.

   ›Reveal solutionSolution

   Testosterone is the principal male sex hormone (androgen) secreted by the Leydig cells of the testis.

   In the human male reproductive system, the interstitial cells (Leydig cells) present in the testis secrete testosterone under stimulation by luteinising hormone (LH) from the pituitary. Testosterone regulates the development of male secondary sexual characters (facial hair, deepening of voice, muscle growth), supports spermatogenesis in …

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10. CBSE 2023Set ANNUAL1 markMCQ
    Q.Leydig cells secretes

    (a) Estrogens

    (b) Androgens

    (c) Progesterone

    (d) Corticosterone

    ›Reveal solutionSolution

    Leydig (interstitial) cells of the testis secrete androgens (testosterone), which control male secondary sexual characters and spermatogenesis.

    The Leydig cells (interstitial cells) are located in the interstitial spaces (regions) between the seminiferous tubules within each testicular lobule. They secrete a group of hormones called androgens, principally testosterone, which regulate the development, maturation, and function of the male accessory sex organs, control secondary sexual characteristics (like facial hair, deep voice), and act along with FSH to stimulate spermatog …

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11. CBSE 2022Set ZOOLOGY1 markMCQ
    Q.Which cell organelle of spermatid forms acrosome of sperm?

    (i) Mitochondria

    (ii) Golgi body

    (iii) Ribosome

    (iv) Lysosome

    ›Reveal solutionSolution

    The acrosome of the sperm is derived from the Golgi body of the spermatid.

    As a spermatid matures into a spermatozoon (spermiogenesis), its organelles are reorganised. The Golgi complex collects and condenses hydrolytic enzymes into a membrane-bound vesicle that spreads as a cap over the anterior part of the nucleus - the acrosome. These acrosomal enzymes later help the sperm penetrate the layers of th …

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12. CBSE 2020Set WK1 mark
    Q.Define spermatogenesis.

    ›Reveal solutionSolution

    Spermatogenesis = formation of sperms from spermatogonia in the testis.

    Definition. Spermatogenesis is the process by which the immature male germ cells (spermatogonia) are converted into mature spermatozoa (sperms) inside the seminiferous tubules of the testis.

    …

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