Why do cells divide?

• A. To increase organism size only
• B. To produce genetic variation
• C. To divide to replace old cells
• D. Growth, repair, and reproduction

Answer: (D)

Cells divide to support growth, repair, and reproduction. In multicellular organisms, mitosis increases the number of cells so the organism can grow and replace cells that die or are damaged, keeping tissues healthy. It also lets a single cell give rise to new offspring in development or in asexual reproduction. While cell division can produce identical daughter cells for maintenance and growth, genetic variation mainly comes from meiosis, a different division process that occurs during sexual reproduction. So the broader reason for dividing is growth, repair, and reproduction.