[Campbell Biology P.309] During which phase of Meiosis I do homologous chromosomes pair up a... | Practice Question

During which phase of Meiosis I do homologous chromosomes pair up and exchange segments in a process called crossing over?

  • A: Prophase I
  • B: Metaphase I
  • C: Anaphase I
  • D: Telophase I

Explanation

The text under Prophase I explicitly states: 'During early prophase I... each chromosome pairs with its homolog, aligned gene by gene, and crossing over occurs'. The X-shaped regions called chiasmata are the visible evidence of this exchange.