Assertion (A) : A group of animals related by descent and similar in most characters like general appearance , features , size , configuration , etc . , are said to belong to a breed .
Reason (R) : Cross between two breeds of a species naturally not possible .

Options

A. Both A and R are correct and R is the correct explanation of A
B. Both A and R are correct but R is not the correct explanation of A
C. A is true but R is false
D. A is false and R is true

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion (A)**:
- The assertion states that a group of animals that are related by descent and share similar characteristics such as appearance, features, size, and configuration belong to a breed.
- This definition aligns with the biological concept of a breed, where animals of the same breed exhibit phenotypic similarities and share a common ancestry.

2. **Analyzing the Reason (R)**:
- The reason claims that a cross between two breeds of a species is not naturally possible.
- However, this statement is misleading. While animals of different breeds may prefer to mate within their own breed in natural settings, crossbreeding is indeed possible and is often practiced in agriculture to enhance certain traits, such as milk production or growth rate.

3. **Conclusion on Assertion and Reason**:
- Both the assertion and the reason are correct statements individually.
- The assertion correctly describes what constitutes a breed, while the reason correctly identifies that natural mating typically occurs within the same breed.
- However, the reason does not serve as a correct explanation for the assertion, as it implies that crossbreeding cannot occur at all, which is not true in the context of animal breeding practices.

4. **Final Answer**:
- Therefore, the conclusion is that both the assertion and the reason are correct, but the reason is not the correct explanation of the assertion.

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