Human cells normally contain two sex chromosomes. Females have two X chromosomes, and males have an X and a Y chromosome. As a result, about half of babies are born with female sex chromosomes and half are born with male sex chromosomes.
After chromosomes are determined, they further influence sex by affecting which gonads the zygote will develop through the Y chromosome. The Y chromosome contains a gene called SRY, which stands for "sex determining region on the Y chromosome." Of course, the SRY gene is absent on the X chromosome.
- Autosomal chromosomes: "Autosomal simply refers to non-sex chromosomes. So, sticking with the human example, do the math, and you can see that humans have 44 autosomal chromosomes."
- Wile, Dr. Jay L. Exploring Creation With Biology. Apologia Educational Ministries, Inc. 1998
- Genetics: Examining the Basics of Chromosomes
- Grison, Sarah, and Michael S. Gazzaniga. Psychology in Your Life. W.W. Norton & Company, Inc., 2017.