Which process that occurs during meiosis contributes to a gamete having unique genetic material?

• A. Crossing over
• B. DNA replication
• C. Cytokinesis
• D. Mitosis

Answer: (A)

Verified step by step guidance

1. Understand the context of meiosis: Meiosis is a type of cell division that reduces the chromosome number by half, creating four haploid cells, each genetically distinct from the parent cell. It is essential for sexual reproduction.
2. Identify the key processes in meiosis: Meiosis consists of two stages, Meiosis I and Meiosis II. During Meiosis I, homologous chromosomes are separated, and during Meiosis II, sister chromatids are separated.
3. Focus on genetic variation: Genetic variation in gametes is primarily introduced during Meiosis I through a process called crossing over. This occurs during prophase I when homologous chromosomes pair up and exchange segments of DNA.
4. Explain crossing over: Crossing over involves the physical exchange of chromosome segments between non-sister chromatids of homologous chromosomes. This results in new combinations of alleles, contributing to genetic diversity in gametes.
5. Differentiate from other processes: DNA replication occurs before meiosis begins, ensuring each chromosome consists of two sister chromatids. Cytokinesis is the division of the cytoplasm, and mitosis is a separate process of cell division that does not contribute to genetic variation in the same way as crossing over during meiosis.