The immature male germ cells undergo division to produce sperms by the process of spermatogenesis. Choose the correct one with reference to above.

Options

A. Spermatogonia have 46 chromosomes and always undergo meiotic cell division
B. Primary spermatocytes divide by mitotic cell division
C. Secondary spermatocytes have 23 chromosomes and undergo second meiotic division
D. Spermatozoa are transformed into spermatids

Explanation

**Step-by-Step Solution:**

1. **Understanding Spermatogenesis**: Spermatogenesis is the biological process through which immature male germ cells develop into mature sperm cells. This process involves several stages of cell division and differentiation.

2. **Identifying Germ Cell Types**: The process begins with spermatogonia, which are the immature male germ cells. These cells are diploid, meaning they contain 46 chromosomes.

3. **Mitosis of Spermatogonia**: Spermatogonia undergo mitotic division to produce primary spermatocytes. Mitosis is an equational division that maintains the chromosome number.

4. **Meiosis of Primary Spermatocytes**: Primary spermatocytes undergo the first meiotic division (meiosis I) to produce secondary spermatocytes. This division reduces the chromosome number from 46 to 23, making secondary spermatocytes haploid.

5. **Meiosis II**: Secondary spermatocytes then undergo the second meiotic division (meiosis II) to produce spermatids, which are also haploid and contain 23 chromosomes.

6. **Transformation into Spermatozoa**: Finally, spermatids undergo structural changes to become spermatozoa (mature sperm cells). This transformation involves significant morphological changes but does not involve further division.

7. **Evaluating Statements**: Now, we evaluate the provided statements:
- **Statement 1**: "Spermatogonia have 46 chromosomes." - This is correct.
- **Statement 2**: "Primary spermatocytes divide by mitotic division." - This is incorrect; they undergo meiotic division.
- **Statement 3**: "Secondary spermatocytes have 23 chromosomes and undergo second meiotic division." - This is correct.
- **Statement 4**: "Spermatozoa are transformed into spermatids." - This is incorrect; spermatids transform into spermatozoa.

8. **Conclusion**: The correct statement regarding spermatogenesis is that secondary spermatocytes have 23 chromosomes and undergo the second meiotic division.

**Final Answer**: The correct option is that secondary spermatocytes have 23 chromosomes and undergo the second meiotic division.

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