Sex chromosomes of birds are

Options

A. ZW-ZZ
B. ZZ-WW
C. XX-XY
D. XO-XX

Answer

**Step-by-Step Solution:**

1. **Understanding Sex Chromosomes**: In many organisms, sex is determined by specific chromosomes known as sex chromosomes. In birds, the system of sex determination is different from that in mammals.

2. **Identify the Chromosomal System in Birds**: Birds utilize the ZW sex-determination system. In this system, males are typically represented by the ZZ chromosome pair, while females are represented by the ZW chromosome pair.

3. **Comparison with Other Organisms**: To clarify, in mammals (like humans), the sex chromosomes are XX for females and XY for males. However, in birds, this system is reversed, where the female is ZW and the male is ZZ.

4. **Conclusion**: Therefore, the sex chromosomes of birds are ZW for females and ZZ for males.

**Final Answer**: The sex chromosomes of birds are ZW (female) and ZZ (male).

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