A : Crossing over is exchange of genetic material between non-homologous chromosomes.
R : it produces new linkages.

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 and 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 statements, then mark (4)

Answer

To solve the assertion-reason question, we need to analyze both the assertion (A) and the reason (R) provided:

**Assertion (A):** Crossing over is the exchange of genetic material between non-homologous chromosomes.
**Reason (R):** It produces new linkages.

### Step-by-Step Solution:

1. **Understanding Crossing Over:**
- Crossing over is a genetic process that occurs during meiosis, specifically in prophase I. It involves the exchange of genetic material between non-sister chromatids of homologous chromosomes, not non-homologous chromosomes.
- Therefore, the assertion is incorrect because it states that crossing over occurs between non-homologous chromosomes.

2. **Analyzing the Reason:**
- The reason states that crossing over produces new linkages. However, crossing over results in genetic recombination, which creates new combinations of alleles but does not produce new linkages in the sense of linking genes together.
- Thus, the reason is also incorrect.

3. **Conclusion:**
- Since both the assertion and the reason are incorrect, we can conclude that the correct answer is that both A and R are false.

### Final Answer:
Both assertion (A) and reason (R) are false.

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