Which of the following processes happens during Meiosis I?

• A. Crossing over occurs during Meiosis II
• B. DNA replication occurs
• C. Sister chromatids separate
• D. Homologous chromosomes separate

Answer: (D)

Verified step by step guidance

1. Understand that 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.
2. Meiosis consists of two stages: Meiosis I and Meiosis II. Each stage has its own specific events.
3. During Meiosis I, homologous chromosomes pair up and exchange genetic material in a process called crossing over, which occurs during prophase I.
4. In Meiosis I, homologous chromosomes (each consisting of two sister chromatids) are separated into two different cells. This is the key event that distinguishes Meiosis I from Meiosis II.
5. DNA replication does not occur during Meiosis I; it occurs prior to meiosis during the S phase of the cell cycle. Sister chromatids separate during Meiosis II, not Meiosis I.