ZZ/ZW type of sex determination is seen in

Options

A. platypus
B. snails
C. cockroach
D. peacock

Explanation

### Step-by-Step Text Solution:

1. **Understanding ZZ/ZW Sex Determination**:
- The ZZ/ZW sex determination system is a type of chromosomal sex determination found in certain species. In this system, males have two identical sex chromosomes (ZZ), while females have two different sex chromosomes (ZW).

2. **Identifying Organisms with ZZ/ZW System**:
- This system is primarily observed in some birds and reptiles. For example, in birds, the male typically has two Z chromosomes (ZZ), whereas the female has one Z and one W chromosome (ZW).

3. **Characteristics of Sex Chromosomes**:
- In the ZZ/ZW system, the Z chromosome is considered to be homomorphic in males (both are the same), while in females, the Z and W chromosomes are heteromorphic (different from each other).

4. **Conclusion**:
- Therefore, the ZZ/ZW type of sex determination is seen in certain birds and reptiles.