Diploid chromosome number being 8, what shall be the number of chromatids in each daughter after meiosis I

Options

A. 8
B. 4
C. 2
D. 16

Answer

To solve the question regarding the number of chromatids in each daughter cell after meiosis I when the diploid chromosome number is 8, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Diploid Number**: The diploid chromosome number (2n) is given as 8. This means that in a somatic cell, there are 8 chromosomes.

2. **Identify the Chromosome Count in Meiosis**: Meiosis consists of two divisions: meiosis I and meiosis II. In meiosis I, the homologous chromosomes are separated, and this is often referred to as the reduction division because it reduces the chromosome number by half.

3. **Calculate the Haploid Number**: Since the diploid number is 8 (2n = 8), the haploid number (n) after meiosis I will be half of the diploid number.
\[ n = \frac{8}{2} = 4 \]
This means that each daughter cell will have 4 chromosomes after meiosis I.

4. **Determine the Number of Chromatids**: Each chromosome consists of two sister chromatids before meiosis I begins. Therefore, when we have 4 chromosomes in each daughter cell after meiosis I, each of these chromosomes still has 2 chromatids.
\[ \text{Total chromatids in each daughter cell} = 4 \text{ chromosomes} \times 2 \text{ chromatids/chromosome} = 8 \text{ chromatids} \]

5. **Conclusion**: After meiosis I, each daughter cell will contain 4 chromosomes, and since each chromosome has 2 chromatids, the total number of chromatids in each daughter cell after meiosis I is 8.

### Final Answer:
The number of chromatids in each daughter cell after meiosis I is **8**.