Which phase of meiosis involves separation of homologous chromosomes?

• A. Prophase I
• B. Metaphase I
• C. Anaphase I
• D. Telophase II

Answer: (C)

During meiosis I the key event is the separation of homologous chromosomes. After the homologs pair up and crossing over occurs in prophase I, they line up as pairs at the center in metaphase I. In anaphase I, the spindle pulls each member of every homologous pair toward opposite poles, so the homologs separate from each other. The sister chromatids stay attached at this stage, only separating later in anaphase II. This step reduces the chromosome number from diploid to haploid, which is the main purpose of meiosis I.