Crossing over is an important event in meiosis because it increases genetic diversity. This process allows chromosomes to exchange segments of DNA, leading to new combinations of genes. As a result, the offspring produced through sexual reproduction have a mix of traits from both parents, which can contribute to better adaptation and survival in changing environments.
Crossing over occurs during the prophase I phase of meiosis. This is when paired chromosomes come together and exchange genetic material before the cells divide.