7.4: Cell Division and Sex Determination

Cells in the body reproduce through two distinct processes. Mitosis is somatic cell division in which one diploid cell divides into two identical diploid cells, each containing a full complement of genetic information. This process supports growth and tissue maintenance.

Meiosis is the reductional process that produces gametes through gametogenesis. One diploid cell divides through two sequential divisions to produce four haploid cells, each containing only half of the genetic information. This process generates new allele combinations that contribute to genetic diversity in offspring.

In mammals, biological sex is determined by a specific pair of chromosomes. Females possess two X chromosomes (XX), while males have one X and one Y chromosome (XY). All other chromosomes, aside from these sex chromosomes, are called autosomes. Since females can only contribute an X chromosome to their offspring while males can contribute either an X or a Y, it is the male parent that determines the sex of the offspring.

The image below illustrates binary fission, mitosis, and meiosis.

Image credit: Wikipedia Cell Divison, Link to binary fission, mitosis, and meiosis image

---