Which type of germ cells contain 23 chromosomes

Options

A. Spermatogonia
B. Secondary spermatocytes
C. Primary spermatocytes
D. None of the above

Explanation

To determine which type of germ cells contain 23 chromosomes, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Germ Cells**: Germ cells are specialized cells involved in reproduction. In males, these include spermatogonia, primary spermatocytes, and secondary spermatocytes.

2. **Chromosome Count in Spermatogonia**: Spermatogonia are the initial germ cells and are diploid. This means they contain two sets of chromosomes, totaling 46 chromosomes (23 pairs).

3. **Chromosome Count in Primary Spermatocytes**: Some spermatogonia develop into primary spermatocytes. These cells also remain diploid and contain 46 chromosomes.

4. **Meiosis and Chromosome Count**: Primary spermatocytes undergo meiosis, a type of cell division that reduces the chromosome number by half. This process consists of two divisions: meiosis I and meiosis II.

5. **Formation of Secondary Spermatocytes**: After the first meiotic division (meiosis I), primary spermatocytes divide to form two secondary spermatocytes. These secondary spermatocytes are haploid, meaning they contain only one set of chromosomes.

6. **Chromosome Count in Secondary Spermatocytes**: Since secondary spermatocytes are haploid, they contain 23 chromosomes.

7. **Conclusion**: Therefore, the type of germ cells that contain 23 chromosomes are the secondary spermatocytes.

### Final Answer:
The germ cells that contain 23 chromosomes are **secondary spermatocytes** (Option B).

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