Assertion: Crossing over leads to recombination of genetic material on the two chromosomes.
Reason: Crossing over is the exchange of genetic material between two homologous chromosomes.

Options

A. If both assertion and reason are true and reason is the correct explantion of assertion
B. If both assertion and reason are true but reason is not the correct explnantion of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To analyze the assertion and reason provided in the question, we can break down the concepts involved step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Crossing over leads to recombination of genetic material on the two chromosomes."
- This means that during the process of crossing over, genetic material is exchanged between two chromosomes, resulting in new combinations of genes.

2. **Understanding the Reason**:
- The reason states that "Crossing over is the exchange of genetic material between two homologous chromosomes."
- Homologous chromosomes are pairs of chromosomes that have the same genes at the same loci but may have different alleles (variations of a gene).

3. **Linking Assertion and Reason**:
- The assertion is correct because crossing over indeed results in the recombination of genetic material, which is a fundamental aspect of genetic diversity.
- The reason is also correct because crossing over specifically occurs between homologous chromosomes, which allows for the exchange of genetic material.

4. **Conclusion**:
- Since both the assertion and the reason are correct, and the reason provides a valid explanation for the assertion, the final conclusion is that both statements are true and the reason correctly explains the assertion.

### Final Answer:
Both the assertion and the reason are correct, and the reason is the correct explanation of the assertion.

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