In which of the following female is heterogametic ?

Options

A. Drosophila
B. Human
C. Fowl
D. Honey bee

Answer

To determine which of the following females is heterogametic, we need to understand the concept of heterogametic sex. Heterogametic individuals produce two types of gametes due to the presence of two different sex chromosomes.

### Step-by-Step Solution:

1. **Define Heterogametic**:
- Heterogametic refers to an individual that produces two different types of gametes. This is typically due to the presence of two different sex chromosomes.

2. **Identify the Sex Chromosomes in Different Organisms**:
- **Drosophila (Fruit Fly)**: In Drosophila, females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). Thus, females produce only one type of gamete (X).
- **Humans**: In humans, females also have two X chromosomes (XX), while males have one X and one Y chromosome (XY). Therefore, females produce only X gametes, while males produce two types (X and Y).
- **Fowl (Birds)**: In birds, the sex determination system is different. Females have one Z and one W chromosome (ZW), while males have two Z chromosomes (ZZ). This means that females produce two types of gametes (Z and W).
- **Honeybee**: In honeybees, females are diploid (having two sets of chromosomes) and produce only one type of gamete, while males are haploid (having one set of chromosomes) and produce one type of gamete.

3. **Determine the Heterogametic Female**:
- From the analysis above, we see that in Drosophila, humans, and honeybees, females are not heterogametic as they produce only one type of gamete. However, in fowls (birds), females are heterogametic because they produce two types of gametes (Z and W).

4. **Conclusion**:
- The correct answer is **C. Fowl**.