Question

Given below is the schematic representation of spermatogenesis in human males:

Choose the option that shows the correct labelling of ‘I’, ‘II’, ‘III’ and ‘IV’ in the given diagram.

• A. spermatozoa, spermatid, sec. spermatocyte, spermatogonia
• B. spermatid, spermatogonia, sec. spermatocyte, spermatozoa
• C. spermatogonia, sec. spermatocyte, spermatozoa, spermatid
• D. spermatogonia, sec. spermatocyte, spermatid, spermatozoa

Hint:

In spermatogenesis, the sequence of cell divisions is: Spermatogonia \( \to \) Primary Spermatocytes \( \to \) Secondary Spermatocytes \( \to \) Spermatids \( \to \) Spermatozoa.

Answer 1

The Correct Option is D

Spermatogenesis and Stage Labeling

Step 1: Understanding Spermatogenesis

Spermatogenesis is the male process of sperm cell development within the seminiferous tubules of the testes. Its key phases are:

• Spermatogonia: Primordial germ cells that undergo mitosis to produce primary spermatocytes.
• Primary Spermatocytes: Cells that undergo meiosis I to yield secondary spermatocytes.
• Secondary Spermatocytes: Cells that undergo meiosis II to yield spermatids.
• Spermatids: Cells that mature through spermiogenesis into spermatozoa (fully developed, motile sperm).

Step 2: Analyzing the Diagram

The accompanying diagram illustrates the stages of spermatogenesis. Based on the process description:

• I denotes spermatogonia, the undifferentiated germ cells that proliferate to create primary spermatocytes.
• II denotes secondary spermatocytes, resulting from the initial meiotic division of primary spermatocytes.
• III denotes spermatids, formed post the second meiotic division of secondary spermatocytes.
• IV denotes spermatozoa, the terminal mature sperm cells developed after spermiogenesis.

Step 3: Conclusion

The correct identification of 'I', 'II', 'III', and 'IV' on the diagram corresponds to: Option (D): Spermatogonia, Secondary Spermatocyte, Spermatid, Spermatozoa.