Assertion:Interspecific mating often produce a more vigorous but sterile `F_1` hybrids .
Reason:Reproductive isolation does not let evolution to occur.

Options

A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion
B. If both Assertion and Reason are true and Reason is not the correct explanation of Assertion
C. If Assertion is true but Reason is false.
D. If both Assertion and Reason are false

Answer

To analyze the given assertion and reason, we will break down the statements step by step.

### Step 1: Understanding the Assertion
The assertion states that "interspecific mating often produces a more vigorous but sterile F1 hybrids."

- **Explanation**: Interspecific mating refers to mating between different species. When two different species mate, they can produce hybrids. These hybrids can sometimes exhibit hybrid vigor, meaning they are often stronger or more robust than their parent species. However, these hybrids are typically sterile, meaning they cannot reproduce. A classic example of this is the mule, which is a hybrid of a horse and a donkey. Mules are generally strong and resilient but cannot reproduce.

### Step 2: Understanding the Reason
The reason states that "reproductive isolation does not let evolution to occur."

- **Explanation**: Reproductive isolation is a mechanism that prevents species from mating with each other. This can occur through various means, such as temporal isolation (different mating seasons), behavioral isolation (different mating behaviors), or mechanical isolation (incompatible reproductive organs). While it might seem that reproductive isolation would hinder evolution, it actually plays a crucial role in the process. By preventing gene flow between populations, reproductive isolation allows for genetic divergence and the evolution of new species over time.

### Step 3: Evaluating the Truth of the Statements
- The assertion is **true**: Interspecific mating can produce vigorous but sterile hybrids.
- The reason is **false**: Reproductive isolation does not prevent evolution; rather, it facilitates it by allowing populations to diverge genetically.

### Conclusion
Since the assertion is true and the reason is false, the correct answer is that the assertion is true, but the reason is false.

### Final Answer
- **Assertion**: True
- **Reason**: False