Which mechanism during meiosis contributes to genetic diversity aside from crossing over?

• A. DNA replication
• B. Independent assortment
• C. Mitosis
• D. Cytokinesis

Answer: (B)

Genetic diversity in meiosis comes from how chromosome pairs separate, not just from crossing over. The key idea is independent assortment: during metaphase I, homologous chromosome pairs line up in random orientations, and when they separate in anaphase I, the maternal or paternal member of each pair can go to either daughter cell independently. This random distribution creates many possible combinations of maternal and paternal chromosomes in gametes, vastly increasing variation even without crossing over. For humans, with 23 chromosome pairs, this alone yields about 2^23 possible gamete chromosome combinations, contributing enormous diversity. Other processes don’t shuffle alleles: DNA replication duplicates DNA but doesn’t mix alleles; mitosis creates somatic, not gamete, cells and doesn’t produce new allele combinations; cytokinesis just divides the cytoplasm.