ZZ/ZW type of sex determination is seen in

Options

A. Platypus
B. Snails
C. Cockroach
D. Peacock

Answer

To solve the question regarding the ZZ/ZW type of sex determination, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Understand ZZ/ZW Sex Determination**:
- In ZZ/ZW sex determination, males have two similar sex chromosomes (ZZ), while females have two different sex chromosomes (ZW). This is a common system found in birds, some reptiles, and some insects.

2. **Evaluate the Options**:
- **Option A: Platypus**:
- The platypus is a mammal that exhibits XY sex determination (males are XY and females are XX). This option is incorrect.

- **Option B: Snails**:
- Snails belong to the mollusks, which typically exhibit X0/X0 or XY sex determination. Males may have one X chromosome or none, while females have two X chromosomes. This option is also incorrect.

- **Option C: Cockroach**:
- Cockroaches have an X0/X0 sex determination system. Males can have either one X chromosome or none, while females have two X chromosomes. This option is incorrect as well.

- **Option D: Peacock**:
- Peacocks are birds and exhibit ZZ/ZW sex determination. Males have ZZ chromosomes, and females have ZW chromosomes. This option is correct.

3. **Conclusion**:
- After analyzing all the options, we conclude that the ZZ/ZW type of sex determination is seen in **peacock**.

### Final Answer:
The correct answer is **Option D: Peacock**.

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