The number of bivalents in Prophase I of meiosis are 10. How many chromosomes will be in Anaphase II of meiosis at each pole?

Options

A. 5
B. 10
C. 20
D. 40

Answer

To solve the question, we need to analyze the information provided about meiosis and the concept of bivalents.

### Step-by-Step Solution:

1. **Understanding Bivalents**:
- A bivalent is a pair of homologous chromosomes that come together during Prophase I of meiosis. Each bivalent consists of two chromosomes.

2. **Given Information**:
- The question states that there are 10 bivalents in Prophase I of meiosis.

3. **Calculating Total Chromosomes**:
- Since each bivalent consists of 2 chromosomes, the total number of chromosomes can be calculated as:
\[ \text{Total Chromosomes} = \text{Number of Bivalents} \times 2 = 10 \times 2 = 20 \text{ chromosomes} \]

4. **Understanding Meiosis Stages**:
- In Meiosis I, during Anaphase I, homologous chromosomes (the bivalents) are separated into two daughter cells. Each daughter cell will receive half of the total chromosomes.
- Therefore, after Anaphase I, each daughter cell will have:
\[ \text{Chromosomes per Daughter Cell} = \frac{20}{2} = 10 \text{ chromosomes} \]

5. **Meiosis II**:
- In Meiosis II, which is similar to mitosis, the sister chromatids of each chromosome are separated.
- Therefore, during Anaphase II, each of the 10 chromosomes in the daughter cells will split into two sister chromatids.

6. **Final Count in Anaphase II**:
- At the end of Anaphase II, each pole will have:
\[ \text{Chromosomes at Each Pole} = 10 \text{ chromosomes} \]

### Conclusion:
The number of chromosomes at each pole during Anaphase II of meiosis will be **10 chromosomes**.

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