Number of chromosmes in secondary oocyte stage in human is

Options

A. 23
B. 46
C. 18
D. 20

Answer

To determine the number of chromosomes in the secondary oocyte stage in humans, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Chromosome Number in Humans**:
- Humans have a total of 46 chromosomes, which are arranged in 23 pairs. This is the diploid number (2n).

2. **Identify the Primary Oocyte Stage**:
- The primary oocyte is diploid (2n), meaning it contains 46 chromosomes. This stage occurs before meiosis.

3. **Meiosis Process**:
- The primary oocyte undergoes meiosis, which is a type of cell division that reduces the chromosome number by half.
- Meiosis consists of two divisions: meiosis I and meiosis II.

4. **Formation of Secondary Oocyte**:
- During meiosis I, the primary oocyte divides to form a secondary oocyte and a polar body.
- The secondary oocyte is formed after the first meiotic division and is haploid (n).

5. **Determine the Chromosome Count in Secondary Oocyte**:
- Since the secondary oocyte is haploid, it contains half the number of chromosomes compared to the primary oocyte.
- Therefore, the secondary oocyte has 23 chromosomes (n).

6. **Conclusion**:
- The number of chromosomes in the secondary oocyte stage in humans is 23.

### Final Answer:
The number of chromosomes in the secondary oocyte stage in humans is **23**.

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