BIOL 1010 Chapter Notes -Sister Chromatids, Turner Syndrome, Monosomy
Document Summary
Humans have 23 pairs of homologous chromosomes - therefore we have 46 chromosomes. 22 pairs of homologous chromosomes exactly the same in both male and female karyotypes. One pair of chromosomes ( mammals) that are sex chromosomes that determine sex. In males, there is an x and a y chromosome (xy) Females lack a y chromosome and have two x chromosomes (xx) Autosomes: a chromosome that carries a genetic trait. Sex chromosomes: the chromosomes that determines the sex of the individual. Due to nutrition by the mother during pregnancy. Coronary artery disease: multiple causes, including genetic predisposition (particular genotype that increases your risk) Incidence: can be up to 1/15 in western population. Monosomics that lack a single copy of a chromosome (monosomy) Trisomics that carry an additional copy of the chromosome (trisomy) Trisomy 21, an additional chromosome 21 in the karyotype , owing to nondisjunction during meiosis. This is what happens to 97% of all down syndrome cases.