If haploid chromosome number is 10 the monosomic number shall be

Options

A. 9
B. 18
C. 10
D. 19

Answer

To solve the question regarding the monosomic number when the haploid chromosome number is given as 10, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Terms**:
- **Haploid Number (n)**: This is the number of chromosomes in a gamete (sperm or egg). In this case, it is given as 10.
- **Diploid Number (2n)**: This is the total number of chromosomes in a somatic cell, which is double the haploid number.

2. **Calculate the Diploid Number**:
- Since the haploid number (n) is 10, the diploid number (2n) can be calculated as:
\[ 2n = 2 \times 10 = 20 \]

3. **Define Monosomy**:
- Monosomy refers to the condition where there is a loss of one chromosome from the diploid set. Therefore, the monosomic number can be calculated by subtracting one from the diploid number.

4. **Calculate the Monosomic Number**:
- To find the monosomic number, we subtract 1 from the diploid number:
\[ \text{Monosomic Number} = 2n - 1 = 20 - 1 = 19 \]

5. **Conclusion**:
- Therefore, if the haploid chromosome number is 10, the monosomic number shall be 19.

### Final Answer:
The monosomic number is **19**.

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