Assertion :- In a mixed population those that can better-adapt, survive and increase in population size.
Reason :- Better adaptability made the animal reproductively fit.

Options

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

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Assertion:**
- The assertion states that in a mixed population, those organisms that can better adapt to their environment will survive and increase in population size. This aligns with the principles of natural selection, where organisms that are better suited to their environment have a higher chance of survival and reproduction.

2. **Understanding the Reason:**
- The reason provided is that better adaptability makes an animal reproductively fit. This means that organisms that can adapt well to their environment are more likely to reproduce successfully, passing on their advantageous traits to the next generation.

3. **Evaluating the Truth of the Assertion:**
- The assertion is true because it reflects the concept of natural selection. Organisms that are better adapted to their environment tend to survive longer and reproduce more, leading to an increase in their population size.

4. **Evaluating the Truth of the Reason:**
- The reason is also true, as it explains that adaptability contributes to reproductive fitness. If an organism is well adapted, it is more likely to survive and reproduce, thus increasing its chances of passing on its genes.

5. **Determining the Relationship Between Assertion and Reason:**
- The reason correctly explains the assertion. The assertion states that better-adapted organisms survive and increase in population size, and the reason explains why this is the case—better adaptability leads to higher reproductive fitness.

6. **Conclusion:**
- Both the assertion and the reason are true, and the reason provides a correct explanation for the assertion. Therefore, the correct answer is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.

**Final Answer:**
- Both assertion and reason are true, and the reason correctly explains the assertion.

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