An animal species has 40 chromosomes in its somatic cells. The number of chromosomes present in the somatic cells of a monosomic individual of the same species is

Options

A. 20
B. 40
C. 39
D. 19

Answer

To solve the problem, we need to determine the number of chromosomes in the somatic cells of a monosomic individual of a species that has 40 chromosomes in its somatic cells.

### Step-by-Step Solution:

1. **Understand the Total Chromosome Count**:
- The problem states that the animal species has 40 chromosomes in its somatic cells. This indicates that the species is diploid (2n), meaning it has two sets of chromosomes.

2. **Identify the Chromosome Count in Monosomy**:
- Monosomy refers to a condition where one chromosome is missing from a pair. In a diploid organism, if one chromosome is missing, the total number of chromosomes is reduced by one.

3. **Calculate the Chromosome Count for a Monosomic Individual**:
- Since the total number of chromosomes in the normal diploid individual is 40 (2n = 40), we can calculate the number of chromosomes in a monosomic individual as follows:
\[ \text{Number of chromosomes in monosomic individual} = 40 - 1 = 39 \]

4. **Conclusion**:
- Therefore, the number of chromosomes present in the somatic cells of a monosomic individual of the same species is **39**.

### Final Answer:
The number of chromosomes present in the somatic cells of a monosomic individual is **39**.

---