Meiosis creates genetic diversity by which mechanisms?

• A. Random orientation
• B. Segregation of homologous chromosomes
• C. Crossing over and random orientation
• D. Spindle formation

Answer: (C)

Genetic diversity in meiosis comes from two processes: crossing over and independent assortment. During prophase I, homologous chromosomes pair up and exchange segments between non-sister chromatids. This recombination creates chromatids with new combinations of maternal and paternal alleles, so the resulting gametes can carry allele arrangements not present in either parent.

Then, as homologous chromosome pairs align during metaphase I, their orientation on the spindle is random. Which member of each pair ends up in a given gamete is independent of other pairs, producing many possible combinations of chromosomes in the gametes. The number of possible outcomes is 2^n, where n is the haploid number of chromosomes (humans have 23, leading to a vast variety).

Spindle formation is essential for division, but it doesn’t itself create new allele combinations. Segregation ensures one chromosome from each pair goes to a gamete; the diversity comes from crossing over and this random orientation.