The number of sex chromosomes in human primary spermatocyte is

Options

A. 4
B. 4 or 2
C. 2
D. 1

Answer

To determine the number of sex chromosomes in a human primary spermatocyte, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Spermatogenesis**:
- Spermatogenesis is the process of sperm formation that occurs in the testes of human males. It begins with germ cells known as spermatogonia.

2. **Chromosome Number in Spermatogonia**:
- Spermatogonia are diploid cells, meaning they contain two sets of chromosomes. In humans, this equates to 46 chromosomes in total, which consist of 23 pairs.

3. **Formation of Primary Spermatocytes**:
- Through the process of mitosis, spermatogonia divide to produce primary spermatocytes. Since this process does not change the chromosome number, primary spermatocytes also remain diploid.

4. **Identifying Sex Chromosomes**:
- Out of the 23 pairs of chromosomes, 22 pairs are autosomes (non-sex chromosomes), and 1 pair consists of sex chromosomes. In males, these sex chromosomes are one X chromosome and one Y chromosome.

5. **Conclusion**:
- Therefore, the number of sex chromosomes in a human primary spermatocyte is 2 (one X and one Y).

### Final Answer:
The number of sex chromosomes in a human primary spermatocyte is **2**.

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