Assertion (A): Recombination and crossing over take place in meiosis I.
Reason (R ): In the process of meiosis two stages of DNA replication take place.

Options

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

Explanation

### Step-by-Step Text Solution:

1. **Understanding the Assertion (A)**: The assertion states that "Recombination and crossing over take place in meiosis I." This is true because during meiosis I, specifically in prophase I, homologous chromosomes pair up and exchange segments of genetic material, a process known as crossing over. This results in genetic recombination.

2. **Understanding the Reason (R)**: The reason states that "In the process of meiosis, two stages of DNA replication take place." This statement is false. In meiosis, DNA replication occurs only once, prior to meiosis I, during the S phase of interphase. After this, meiosis proceeds through two rounds of division (meiosis I and meiosis II) without any further DNA replication.

3. **Evaluating the Relationship**: Since the assertion is true and the reason is false, we conclude that the reason does not correctly explain the assertion.

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