Final answer:
Crossing-over, or recombination, is a process during meiosis that leads to genetic variation by exchanging genetic material between non-sister chromatids. It creates unique combinations of genes on chromosomes, contributing to genetic diversity in offspring.
Step-by-step explanation:
Crossing-over, also known as recombination, is a process that occurs during meiosis and contributes to genetic variation. It involves the exchange of genetic material between non-sister chromatids of homologous chromosomes. This exchange creates unique combinations of genes on the chromosomes, leading to genetic diversity in offspring.
During crossing-over, homologous chromosomes line up in pairs and exchange segments of DNA. This process can happen multiple times within a pair of homologous chromosomes, resulting in different recombinant chromatids with varying combinations of maternal and paternal genes. By generating new gene combinations, crossing-over ensures genetic variation among offspring.