Answer the following question given this paragraph: 

When homologous chromosomes form pairs during prophase I of meiosis I, crossing-over can occur. Crossing-over is the exchange of genetic material between non-sister chromatids of homologous chromosomes. It results in new combinations of genes on each chromosome.


Q: When do homologous chromosomes form pairs?

 Choices:

- mitosis

- metathesis

- transcripton

- meiosis

A:
meiosis
