Which one is correct

Options

A. Meiosis I occurs in primary spermatocyte
B. Meiosis I occurs in secondary spermatocyte
C. Meiosis I takes place in spermatids
D. Meiosis II occurs in spermatids.

Answer

To solve the question, we need to analyze each option regarding the process of spermatogenesis, which is the formation of sperm cells in males.

### Step-by-Step Solution:

1. **Understanding Spermatogenesis**:
- Spermatogenesis begins with spermatogonia, which are the stem cells in the testes.

2. **Formation of Primary Spermatocyte**:
- Spermatogonia undergo mitotic division to produce primary spermatocytes.

3. **Meiosis I**:
- Primary spermatocytes undergo meiosis I, resulting in the formation of secondary spermatocytes.
- This confirms that Option 1 is correct: "Meiosis I occurs in primary spermatocyte."

4. **Meiosis II**:
- Secondary spermatocytes then undergo meiosis II, which leads to the formation of spermatids.
- Therefore, Option 2 is incorrect: "Meiosis I occurs in secondary spermatocyte."

5. **Spermatids**:
- Spermatids are the result of meiosis II and do not undergo further division; they mature into spermatozoa.
- This means Option 3 is incorrect: "Meiosis I takes place in spermatids."

6. **Final Confirmation**:
- Since meiosis II occurs in secondary spermatocytes and not in spermatids, Option 4 is also incorrect: "Meiosis II occurs in spermatids."

### Conclusion:
The only correct statement is Option 1: "Meiosis I occurs in primary spermatocyte."