How does meiosis create genetic variation?

• A. Through crossing over and independent assortment, producing diverse haploid gametes.
• B. By cloning identical gametes; no variation occurs.
• C. By doubling chromosome number each generation.
• D. By random fertilization only; meiosis does not contribute to variation.

Answer: (A)

Meiosis creates genetic variation mainly through two processes that shuffle alleles before the gametes are formed. First, crossing over during prophase I swaps pieces of homologous chromosomes, so the resulting chromosomes contain new combinations of alleles that weren’t present in the parent cells. This recombination means each gamete can carry a different mix of genes.

Second, independent assortment during metaphase I and anaphase I randomizes which parental chromosome goes into each gamete. The maternal and paternal chromosomes line up and separate in many possible ways, producing a wide array of chromosome combinations in the gametes.

Because meiosis ends with four haploid cells, each gamete has its own unique set of alleles due to both crossing over and independent assortment. When fertilization occurs, the combination of two diverse gametes generates even more genetic variation in offspring.

Why the other ideas aren’t correct: meiosis does not double chromosome numbers; it reduces them to haploid. It’s not only random fertilization that creates variation—meiosis itself generates diverse gametes through recombination and independent assortment. And cloning identical gametes would imply no variation, which isn’t what meiosis produces.