Final answer:
Crossing over, or chromosomal crossover, occurs during meiosis when homologous chromosomes exchange DNA segments. This process increases genetic diversity by creating new combinations of genes in the offspring.
Step-by-step explanation:
Crossing over, also known as chromosomal crossover, occurs during meiosis when homologous chromosomes exchange DNA segments. This process increases genetic diversity by creating new combinations of genes in the offspring.
When genetic material is exchanged between chromatids, the resulting recombinant chromosomes have a combination of genes from both parents that did not exist before.