At diakinesis, a meiocyte has ten pairs of chromosomes. The chromosomes number expected in each nucleus is, therefore,

Options

A. ten at the end of I division and 5 at the end of 11 division
B. ten at the end of I division and ten at the end of second division
C. five at the end of I division and 5 at the end of second division
D. 20 at the end of I division and ten at the end of second division

Answer

To solve the question regarding the chromosome number expected in each nucleus at diakinesis, follow these steps:

### Step-by-Step Solution:

1. **Understand the Terminology**:
- A meiocyte is a cell that is undergoing meiosis, which is a type of cell division that reduces the chromosome number by half.

2. **Identify the Chromosome Count**:
- The question states that at diakinesis, the meiocyte has 10 pairs of chromosomes. This means that the total number of chromosomes (2n) is 20 (since each pair consists of 2 chromosomes).

3. **Recognize the Stages of Meiosis**:
- Meiosis consists of two main stages: Meiosis I and Meiosis II.
- Meiosis I is a reductional division, meaning it reduces the chromosome number by half.
- Meiosis II is an equational division, meaning the chromosome number remains the same.

4. **Determine the Chromosome Number After Meiosis I**:
- Since the meiocyte starts with 20 chromosomes (2n = 20), after Meiosis I, the two daughter cells will each have half the number of chromosomes. Thus, each daughter cell will have 10 chromosomes (n = 10).

5. **Determine the Chromosome Number After Meiosis II**:
- After Meiosis II, each of the two daughter cells from Meiosis I will divide again, but the number of chromosomes will remain the same. Therefore, all four resulting daughter cells will also have 10 chromosomes each.

6. **Conclusion**:
- At the end of Meiosis I, each nucleus will have 10 chromosomes.
- At the end of Meiosis II, each nucleus will still have 10 chromosomes.

### Final Answer:
The expected chromosome number in each nucleus at diakinesis is 10.

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