A : Most birds posses only the left ovary and left oviduct for conveying the ovum released from the ovary
R : The avian ovary does not form a corpus luteum from the ruptured ovarian follicle which undergoes rapid shrinkage.
(a) If both Assertion & Reason are true and the reason is the correct explanation of the assertion then mark a
(b) If both Assertion & Reason are true but the reason is not the correct explanation of the assertion then mark b
(c) If Assertion is true statement but Reason is false then mark c
(d) If both Assertion and Reason are false statement then mark d

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion then mark (2)
C. If Assertion is true statement but Reason is false then mark (3)
D. If both Assertion and Reason are false statement then Mark (4)

Answer

To solve the question, we need to analyze both the Assertion (A) and the Reason (R) provided.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "Most birds possess only the left ovary and left oviduct for conveying the ovum released from the ovary."
- This is true. In birds, typically, only the left ovary and left oviduct are functional. This adaptation helps in reducing weight for flight.

2. **Understanding the Reason (R)**:
- The reason states that "The avian ovary does not form a corpus luteum from the ruptured ovarian follicle which undergoes rapid shrinkage."
- This is also true. In birds, after ovulation, the ruptured follicle does not develop into a corpus luteum as it does in mammals.

3. **Evaluating the Relationship**:
- Now we need to determine if the reason explains the assertion. The assertion explains a structural adaptation in birds (having only the left ovary and oviduct), while the reason explains a physiological aspect of the avian reproductive system (the lack of corpus luteum formation).
- Although both statements are true, the reason does not directly explain why birds have only the left ovary and oviduct.

4. **Conclusion**:
- Since both the assertion and reason are true, but the reason does not explain the assertion, the correct answer is (b): If both Assertion & Reason are true but the reason is not the correct explanation of the assertion then mark b.

### Final Answer:
(b) If both Assertion & Reason are true but the reason is not the correct explanation of the assertion then mark b.

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