What explains diversity of people?

• A. Mutation
• B. Recombination
• C. Mitosis
• D. Random fertilization

Answer: (B)

Genetic variation in humans mainly comes from how meiosis shuffles genes to create diverse gametes. During meiosis, crossing over exchanges chromosome segments between homologous chromosomes, producing new combinations of alleles on each chromosome. In addition, independent assortment means the chromosomes are sorted into gametes in many possible ways, so each gamete carries a unique mix of maternal and paternal genes. When fertilization occurs, any sperm can unite with any egg, adding even more potential combinations. This combination of recombination and random fertilization generates the vast diversity seen among people. Mitosis doesn’t introduce new allele combinations in offspring, and while mutations do create new alleles over time, the immediate source of broad variation among offspring in a generation is the recombination occurring during meiosis.