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

**Step-by-Step Solution:**

1. **Understanding Spermatogenesis**:
- Spermatogenesis is the process of sperm cell development that begins at puberty in males. It occurs in the testes.

2. **Identifying the Starting Cell**:
- The first cell involved in spermatogenesis is called spermatogonia. This cell is diploid (2n), meaning it contains two sets of chromosomes.

3. **Mitosis of Spermatogonia**:
- Spermatogonia undergo mitosis to produce more spermatogonia and to differentiate into primary spermatocytes.

4. **Meiosis I in Primary Spermatocytes**:
- Primary spermatocytes (which are diploid) undergo the first meiotic division (meiosis I) to produce secondary spermatocytes, which are haploid (n).

5. **Meiosis II in Secondary Spermatocytes**:
- Secondary spermatocytes undergo the second meiotic division (meiosis II) to form spermatids, which are also haploid.

6. **Differentiation of Spermatids**:
- Spermatids then undergo a process of differentiation to become mature spermatozoa (sperm cells). There is no meiosis that occurs in spermatids.

7. **Evaluating the Options**:
- Option A states that meiosis I occurs in primary spermatocytes – this is correct.
- Option B states that meiosis I occurs in secondary spermatocytes – this is incorrect as meiosis II occurs in secondary spermatocytes.
- Option C states that meiosis I takes place in spermatids – this is incorrect as spermatids do not undergo meiosis.
- Option D states that meiosis II occurs in spermatids – this is incorrect as spermatids only undergo differentiation.

8. **Conclusion**:
- The correct statement based on the process of spermatogenesis is Option A: "Meiosis I occurs in primary spermatocytes."

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