Question

Spermatogonia undergo a series of cell divisions to produce sperms. Select the correct statements from the following :
A. Spermatogonia always undergo meiotic cell division.
B. Primary spermatocytes divide mitotically to produce secondary spermatocytes.
C. Secondary spermatocytes, through their second meiotic division, produce haploid spermatids.
D. Spermatids produce spermatozoa through mitosis.
E. Spermatids transform into spermatozoa by spermiogenesis.
Choose the correct answer from the options given below :

• A. C and E only
• B. A, C and E only
• C. B, C and D only
• D. A and E only

Hint:

Logic Tip: The term "genesis" means creation or formation. "Spermatogenesis" is the whole process. "Spermiogenesis" is strictly the final structural transformation (Spermatid $\rightarrow$ Spermatozoa) with zero cell division involved!

Answer 1

The Correct Option is A

Step 1 : Understanding the Question:
This question requires a clear understanding of the stages of spermatogenesis—the process by which male gametes (sperms) are produced. We must distinguish between mitotic proliferation (to maintain cell numbers), meiotic reduction (to create haploid cells), and morphological transformation (to create motile sperm) to determine which statements are accurate.
Step 2 : Key Formulas and Approach:
The sequence of spermatogenesis is as follows:
1. Spermatogonia ($2n$) multiply by Mitosis to maintain the germline.
2. Some differentiate into Primary Spermatocytes ($2n$).
3. Primary Spermatocytes ($2n$) undergo Meiosis I to form two Secondary Spermatocytes ($n$).
4. Secondary Spermatocytes ($n$) undergo Meiosis II to form four Spermatids ($n$).
5. Spermatids ($n$) undergo Spermiogenesis (transformation) to become Spermatozoa ($n$).
Step 3 : Detailed Explanation:

Statement A: Spermatogonia are the stem cells of the male reproductive system. They primarily divide by mitosis to ensure a continuous supply of germ cells throughout reproductive life. They do not "always" undergo meiosis; in fact, the actual meiotic phase starts later in the lineage. Therefore, this statement is incorrect.

Statement B: Primary spermatocytes are diploid cells that initiate the reductional division. They divide through meiosis I, not mitosis, to produce haploid secondary spermatocytes. Therefore, this statement is incorrect.

Statement C: Secondary spermatocytes are haploid cells ($n$) produced after the first meiotic division. They quickly enter meiosis II, which is an equational division, resulting in the formation of four haploid spermatids. This statement is factually correct.

Statement D: Spermatids are the end-products of the second meiotic division. They are already haploid and do not undergo any further cell divisions. Spermatozoa are formed through a process of cellular remodeling, not mitosis. Therefore, this statement is incorrect.

Statement E: The final stage of sperm development is the conversion of non-motile, spherical spermatids into motile, elongated spermatozoa. This specific morphological process—involving the growth of a tail and the formation of an acrosome—is called spermiogenesis. This statement is factually correct.

Step 4 : Final Answer:
Reviewing the biological steps of gamete formation, statements C and E are the only ones that accurately describe the stages of sperm production. Thus, the correct answer is option (A).