Summary
Mitosis and meiosis cell division are reliable gene delivery systems in multicellular, sexually reproducing living things. Our human bodies are designed to have hundreds of different types of somatic cells, but every cell contains the same chromosomes and therefore the same genes when mitosis works correctly. Gametes made by meiosis in diploid species will be haploid. Each gamete has one of every type of chromosome. Pairing of homologous chromosomes and the second round of cell division are the two key events in meiosis which do not happen in mitosis.
How can you be sure you understand how these biological processes work in your body? Start with the chromosomes and genes pictured in Figure 3 and draw these at each of the four stages of mitosis and the eight stages of meiosis. If you end up with two genetically identical cells at the end of mitosis or two gametes that can combine to make a diploid offspring, you understand the genetic importance of cell division.
Figure 3. Prophase of mitosis. Chromosomes are unreplicated during interphase as represented by the four chromosomes with the D/B, E, d/b, and e genes. After going through the S phase, the chromosomes enter prophase where the chromosomes are replicated and have two identical chromatids. Notice the identical nature of the chromatids by looking at how the genes on one chromatid exactly match the genes on the attached chromatid. Image by M. Hanneman, 2021. CC BY-NC-SA 4.0.