Differentiate mitosis and meiosis in outcomes, genetic variation, and ploidy.

• A. Mitosis produces 4 haploid gametes; Meiosis produces 2 identical diploid somatic cells.
• B. Mitosis produces haploid cells; Meiosis produces diploid cells.
• C. Mitosis produces 2 identical diploid somatic cells; Meiosis produces 4 haploid gametes with genetic variation.
• D. Mitosis includes crossing over; Meiosis does not.

Answer: (C)

At the heart of this question is how cell division differs in purpose and outcome: mitosis creates exact copies for growth and repair, while meiosis generates gametes with genetic variation and half the chromosome number. In mitosis, a diploid cell divides once to form two diploid somatic cells that are genetically identical to the original cell (aside from any rare mutations). In meiosis, a diploid cell goes through two rounds of division to yield four haploid gametes, each with a unique set of alleles due to crossing over and independent assortment. This combination of producing two identical diploid cells versus four genetically varied haploid cells with reduced chromosome number best matches the distinctions among outcomes, genetic variation, and ploidy. Crossing over occurs in meiosis, not mitosis, which is another reason mitosis wouldn’t be described as involving genetic shuffling.