Crossing over between homologous chromosomes takes place during

Meiosis I

Explanation:

1. Meiosis (meiosis I and meiosis II) produce four daughter cells from a single cell, each daughter cell contains half the number of chromosomes as compared to parental cell.

2. Meiosis have two cycles, i) meiosis I and ii) meiosis II.

3. In meiosis I, chromosomes first go replication and become double. It is the first step (meiosis I) that generates genetic diversity. During prophase I of meiosis I, homologous chromosomes pair and form synapses, a special step of meiosis.

4. There is crossing over in meiosis I which produce genetic diversity.

5. The four cells produced from a single cell become genetically different due to crossing occur which occur in meiosis I.