If we ignore the effect of crossing over, how many different haploid cells arise by meiosis in a diploid cell having 2n=12

Options

A. 8
B. 16
C. 32
D. 64

Explanation

To solve the question of how many different haploid cells arise by meiosis in a diploid cell with 2n = 12, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Diploid Number**:
- The diploid number (2n) represents the total number of chromosomes in a somatic cell. In this case, 2n = 12 means there are 12 chromosomes in total.

2. **Determine the Haploid Number**:
- The haploid number (n) is half of the diploid number. Therefore, to find n, we divide the diploid number by 2:
\[ n = \frac{2n}{2} = \frac{12}{2} = 6 \]
- So, there are 6 haploid chromosomes.

3. **Calculate the Number of Different Combinations**:
- During meiosis, each chromosome can independently assort into gametes. The number of different combinations of haploid cells can be calculated using the formula:
\[ \text{Number of combinations} = 2^n \]
- Here, n = 6 (the haploid number):
\[ \text{Number of combinations} = 2^6 = 64 \]

4. **Conclusion**:
- Therefore, if we ignore the effect of crossing over, the number of different haploid cells that arise by meiosis from a diploid cell with 2n = 12 is **64**.

### Final Answer:
The number of different haploid cells that arise by meiosis in a diploid cell with 2n = 12 is **64**.

---