Drosophila has four homologous pairs of chromosomes.What is the number of linkage groups in this animal?

Options

A. Four
B. Two
C. Eight
D. Uncertain

Answer

To solve the question regarding the number of linkage groups in Drosophila, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Number of Chromosomes**:
Drosophila has 4 homologous pairs of chromosomes. Each pair consists of two chromosomes, one from each parent.

- **Calculation**:
- Total chromosomes = 4 pairs × 2 = 8 chromosomes.

2. **Understand Linkage Groups**:
A linkage group refers to a set of genes that are located on the same chromosome and are inherited together. The number of linkage groups in a diploid organism corresponds to the number of homologous chromosome pairs.

3. **Determine the Number of Linkage Groups**:
Since Drosophila has 4 pairs of homologous chromosomes, it will have 4 linkage groups. Each pair of homologous chromosomes represents one linkage group.

- **Conclusion**:
- Number of linkage groups = Number of homologous pairs = 4.

4. **Final Answer**:
The number of linkage groups in Drosophila is **4**.