Crossing-over takes place between:

Concept:

• Cell division is of three types:

1. Mitosis - Equational division, occurs in somatic (non-sex) cells
2. Meiosis - Reductional division, occurs in sex cells
3. Amitosis - Direct type of division, occurs in prokaryotes

• Meiosis is the division in which the parent cell divides to form four daughter cells.
• Meiosis can be further divided into two stages - Meiosis I and Meiosis II 
• Prophase I of Meiosis I has 5 sub-stages
• Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis.

Explanation:

• Crossing over refers to the exchange of genetic material between the non-sister chromatids of homologous chromosomes
• Crossing over is also known as recombination
• It occurs in the pachytene stage of meiosis I 
• Crossing over is governed by the enzyme recombinase.

                                                  Diagram showing Crossing over