Which type of cell division is responsible for genetic variation in offspring?

Meiosis is the type of cell division responsible for genetic variation in offspring due to several unique processes that occur during its stages. Unlike mitosis, which produces two identical daughter cells, meiosis results in four genetically distinct cells, which are typically gametes (sperm and eggs) in sexually reproducing organisms.

During meiosis, two key events contribute to genetic variation: independent assortment and crossing over. Independent assortment occurs during the formation of gametes when chromosomes are randomly distributed into daughter cells. This randomness leads to various combinations of maternal and paternal chromosomes in each gamete.

Crossing over happens during prophase I of meiosis, where homologous chromosomes exchange segments of genetic material. This genetic recombination creates new combinations of genes that were not present in either parent, further increasing the variability among offspring.

In contrast, other types of cell division such as mitosis and binary fission result in cells that are genetically identical to the parent cell, which does not contribute to genetic diversity. Replication refers to the process of duplicating DNA, not to the division itself, so it does not inherently create genetic variation either. Therefore, meiosis is essential for producing genetically diverse offspring through sexual reproduction.