Assertion :-In birds, the females have one Z and one W chromosome, whereas male have a pair of Z-chromosomes besides autosomes.
Reason:- In birds, sex of the offsprings is decided by the temprature of surroundings when they are released.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are trur but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is Flase.
D. If both Assertion & Reason are false.

Answer

To solve the question, we will analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that in birds, females have one Z and one W chromosome (ZW), while males have a pair of Z chromosomes (ZZ) along with autosomes.
- This is indeed correct. In birds, the sex determination system is referred to as the ZW system, where females are heterogametic (ZW) and males are homogametic (ZZ).

2. **Understanding the Reason**:
- The reason provided states that in birds, the sex of the offspring is determined by the temperature of the surroundings when they are released.
- This statement is incorrect. In birds, the sex of the offspring is determined by the combination of sex chromosomes inherited from the parents, specifically from the female, not by environmental temperature.

3. **Conclusion**:
- Since the assertion is true (females have ZW and males have ZZ), but the reason is false (sex is not determined by temperature), we conclude that the assertion is true while the reason is false.

4. **Final Answer**:
- The correct option is C: Assertion is true, but the reason is false.