Which of the following are haploid in nature?

Options

A. Spermatids
B. Spermatogonia
C. Primary spermatocytes
D. Secondary spermatocytes

Answer

To determine which of the following are haploid in nature among the options provided (spermatids, spermatogonia, primary spermatocytes, and secondary spermatocytes), we can analyze each type of cell based on their development in spermatogenesis.

### Step-by-Step Solution:

1. **Understanding Spermatogenesis**:
- Spermatogenesis is the process of sperm cell development that occurs in the seminiferous tubules of the testes. It involves several stages of cell division and differentiation.

2. **Identifying Cell Types**:
- **Spermatogonia**: These are the initial germ cells that are diploid (2n) in nature. They undergo mitosis to produce more spermatogonia or differentiate into primary spermatocytes.
- **Primary Spermatocytes**: These cells are formed from spermatogonia and are also diploid (2n). They undergo the first meiotic division.
- **Secondary Spermatocytes**: After the first meiotic division, primary spermatocytes divide to form secondary spermatocytes, which are haploid (n) in nature.
- **Spermatids**: These are the result of the second meiotic division of secondary spermatocytes and are also haploid (n).

3. **Conclusion**:
- From the analysis, we find that:
- **Spermatogonia**: Diploid (2n)
- **Primary Spermatocytes**: Diploid (2n)
- **Secondary Spermatocytes**: Haploid (n)
- **Spermatids**: Haploid (n)
- Therefore, the haploid cells in this context are **secondary spermatocytes and spermatids**.

### Final Answer:
The cells that are haploid in nature are **secondary spermatocytes and spermatids**.

---