Which of the following best describes a key difference between meiosis and mitosis?

• A. Meiosis occurs only in somatic cells, whereas mitosis occurs in gametes.
• B. Crossing over occurs during mitosis but not during meiosis.
• C. Meiosis results in four genetically unique haploid cells, while mitosis produces two identical diploid cells.
• D. Mitosis involves two rounds of cell division, while meiosis involves only one.

Answer: (C)

Verified step by step guidance

1. Step 1: Begin by understanding the definitions of mitosis and meiosis. Mitosis is a type of cell division that results in two genetically identical diploid cells, typically used for growth, repair, and asexual reproduction. Meiosis, on the other hand, is a specialized form of cell division that produces four genetically unique haploid cells, which are gametes (sperm or egg cells) in sexually reproducing organisms.
2. Step 2: Analyze the first statement: 'Meiosis occurs only in somatic cells, whereas mitosis occurs in gametes.' This is incorrect because meiosis occurs in germ cells to produce gametes, while mitosis occurs in somatic cells for growth and repair.
3. Step 3: Analyze the second statement: 'Crossing over occurs during mitosis but not during meiosis.' This is also incorrect because crossing over (exchange of genetic material between homologous chromosomes) occurs during prophase I of meiosis, not during mitosis.
4. Step 4: Analyze the third statement: 'Meiosis results in four genetically unique haploid cells, while mitosis produces two identical diploid cells.' This is correct because meiosis involves two rounds of division (meiosis I and II) and results in haploid cells with genetic variation, while mitosis involves one round of division and produces identical diploid cells.
5. Step 5: Analyze the fourth statement: 'Mitosis involves two rounds of cell division, while meiosis involves only one.' This is incorrect because mitosis involves only one round of division, while meiosis involves two rounds (meiosis I and meiosis II).