True or False: For crossing over to occur, homologous chromosomes must align precisely early in prophase I so that nonsister chromatids can exchange corresponding segments of DNA.

Answer 1

True. For crossing over to occur, homologous chromosomes must align precisely during prophase I of meiosis. This alignment allows nonsister chromatids from homologous chromosomes to exchange corresponding segments of DNA, which is essential for genetic diversity in the resulting gametes.