What is the main purpose of meiosis in sexual reproduction?

The main purpose of meiosis in sexual reproduction is to reduce the chromosome number in gametes. During meiosis, a diploid cell undergoes two rounds of division to produce four haploid cells, which are the gametes (sperm and eggs). This reduction is crucial because it ensures that when fertilization occurs, the resulting zygote has the correct diploid number of chromosomes—half from each parent. This mechanism helps maintain the stability of an organism's chromosome number across generations, preventing an exponential increase in chromosome numbers with each successive generation.

In contrast, producing genetically identical cells is more characteristic of mitosis, which maintains the same chromosome number in daughter cells. DNA replication occurs prior to meiosis during the S phase of the cell cycle and is not the primary purpose of meiosis itself. Forming diploid zygotes happens after fertilization, not during the process of meiosis, so it is not a direct purpose of meiosis.