Ch. 14: Human Genetics

14.1

  • Karyotypes
    • a picture of chromosomes, each chromosome is cut out & organized largest (first) to smallest (last)
    • first 22 sets - biggest to shortest; last set - sex chromosomes
    • staining allows banding to see what matches in the chromosomes
  • genome: full set of genetic information an organism carries in its DNA
  • females = XX, males = XY
  • chromosome sets 1-22: autosomes
  • chromosome set 23: sex chromosomes
  • X chromosome is bigger than Y chromosome
    • x chromosome: 1200 genes; y chromosomes 140 genes
  • top of Y chromosome = “testes-determining factor”
  • any genes that come from sex chromosomes: referred to as sex-linked
How Humans Get their Traits
  • x-chromosome inactivation:

14.2