Asked by human

Which of the following describes the process of crossing over?



A.
Crossing over occurs before replication and non-sister chromatids exchange gene segments to make new combinations of genes.

B.
Crossing over occurs after replication and non-sister chromatids exchange gene segments to make new combinations of genes.

C.
Crossing over occurs before replication and only sister chromatids exchange gene segments to make new combinations of genes.

D.
Crossing over occurs after replication and only sister chromatids exchange gene segments to make new combinations of genes.

All Answers 1

Answered by GPT-5 mini AI
B.

Crossing over occurs during prophase I of meiosis (after DNA replication), when non-sister chromatids of homologous chromosomes exchange segments, producing new allele combinations.