Does sexual reproduction use mitosis, meiosis, both, or neither?

• A. Both mitosis and meiosis
• B. Mitosis
• C. Meiosis
• D. Neither

Answer: (A)

Roles of mitosis and meiosis in sexual reproduction.

Meiosis shapes the genetic makeup of a species by producing gametes—sperm and eggs—that contain half the usual chromosome number. This reduction is crucial so that when two gametes fuse during fertilization, the offspring restore the full diploid chromosome set. Meiosis also mixes genetic material through recombination, creating variation among offspring.

After fertilization, mitotic divisions take over to grow the single-celled zygote into a multicellular organism. Mitosis preserves the chromosome number and generates many genetically identical cells that form tissues and organs during development.

Because sexual reproduction relies on both the creation of haploid gametes and the subsequent growth of the organism through cell division, the best answer is that both processes are involved. If only meiosis occurred, there would be no growth into a multicellular organism; if only mitosis occurred, gametes with half the chromosome number wouldn’t be produced.