Which among the following has 23 chromosomes?

Options

A. Spermatogonia
B. Zygote
C. Secondary oocyte
D. oogonia

Explanation

To determine which among the given options has 23 chromosomes, we can analyze each option step by step:

### Step 1: Understand Chromosome Numbers
- Humans typically have 46 chromosomes, arranged in 23 pairs.
- Gametes (sperm and egg) are produced through meiosis and contain half the number of chromosomes, which is 23.

### Step 2: Analyze Each Option
1. **Spermatogonia**:
- These are the germ cells that give rise to sperm.
- They undergo mitosis and meiosis to eventually form sperm cells.
- Spermatogonia have 46 chromosomes (diploid).

2. **Zygote**:
- This is the fertilized egg formed when a sperm and egg unite.
- The zygote contains 46 chromosomes (diploid) because it combines the chromosomes from both the sperm and the egg.

3. **Secondary Oocyte**:
- This is the result of the first meiotic division in oogenesis.
- It is a haploid cell, meaning it has only 23 chromosomes (haploid).
- This is the correct answer as it represents the female gamete before fertilization.

4. **Oogonia**:
- These are the precursor cells to oocytes and are diploid, containing 46 chromosomes.
- They undergo mitosis and eventually develop into primary oocytes.

### Step 3: Conclusion
- Among the options, the **secondary oocyte** is the only one that has 23 chromosomes.

### Final Answer
The correct option is **Secondary Oocyte**.

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