Which of the following best describes the primary purpose of meiosis in sexually reproducing organisms?

• A. To synthesize proteins required for cell division
• B. To produce identical daughter cells for growth and repair
• C. To increase genetic variation by duplicating chromosomes
• D. To reduce the chromosome number by half, producing haploid gametes

Answer: (D)

Verified step by step guidance

1. Understand the concept of meiosis: Meiosis is a specialized type of cell division that occurs in sexually reproducing organisms. Its primary purpose is to produce haploid gametes (sperm and egg cells) by reducing the chromosome number by half, ensuring that the offspring have the correct diploid chromosome number after fertilization.
2. Clarify the difference between haploid and diploid: Diploid cells contain two sets of chromosomes (one from each parent), while haploid cells contain only one set of chromosomes. Meiosis ensures the production of haploid gametes to maintain genetic stability across generations.
3. Explain the stages of meiosis: Meiosis consists of two consecutive divisions, meiosis I and meiosis II. Meiosis I reduces the chromosome number by separating homologous chromosomes, while meiosis II separates sister chromatids, resulting in four haploid cells.
4. Highlight the role of genetic variation: Meiosis increases genetic variation through processes like crossing over (exchange of genetic material between homologous chromosomes during prophase I) and independent assortment (random distribution of homologous chromosomes during metaphase I). This variation is crucial for evolution and adaptation.
5. Conclude with the primary purpose: The main goal of meiosis is to reduce the chromosome number by half, producing haploid gametes that can combine during fertilization to form a diploid zygote, ensuring genetic continuity and variation in sexually reproducing organisms.