Why it is necessary for homologs to pair during meiosis?

Question

Why is it necessary for homologous chromosomes to pair during meiosis and not during mitosis?

Answer 1

Meiosis will end up with only one of each homologous pair of chromosomes. When they pair up, it's easy for the pairs to be separated from each other during Meisos I.

Mitosis only separates the two sister chromatids of each double-stranded chromosome. The daughter nuclei get one sister chromatid from every chromosome, including homologous chromosomes. So there's no need for them to pair up.

Answer 2

Both to make sure each cell gets one copy of the homologous pairs, and to allow for crossover between the two chromosomes