Crossing Over is a genetic process that occurs during meiosis, where homologous chromosomes exchange segments of their DNA. This exchange results in new combinations of genes, contributing to genetic diversity in offspring. It typically happens during the prophase I stage of meiosis, when chromosomes pair up and form structures called chiasmata. This process is crucial for evolution and adaptation, as it increases variation within a population. The unique combinations of alleles produced through crossing over can lead to different traits in organisms, enhancing their ability to survive in changing environments.