DO NOW 1.What is the correct number of autosomes and sex chromosomes in the somatic cell of a human male? 2. How many autosomes and sex chromosomes would be in the ovum of the human female?
ANSWERS 1. 44 autosomes and 2 sex chromosomes(X and Y) 2. 22 autosomes and an X WHAT DO YOU SEE? WHAT DO YOU SEE? A person with normal color vision sees the number 5. Color blindness (color vision deficiency) ? is a condition in which certain colors cannot be distinguished, and is most commonly due to an inherited condition. ?Problems in distinguishing reds and greens are the most common. A pedigree for color-blindness Normal male Carrier female P1 F1 Carrier female Normal female Colorblind male Normal male Thomas Hunt Morgan was awarded the Nobel Prize in Physiology or Medicine in 1933. The work for which the prize was awarded was completed over a 17year period at Columbia University, commencing in 1910 with his discovery of the white-eyed mutation in the fruit fly, Drosophila. ?Morgan’s work with Drosophila demonstrated that genes for certain traits are located on the X chromosomes. ?These genes are said to be sex-linked. ?These genes do not appear to have corresponding alleles on the Y chromosome. ?Since many sex-linked genes are recessive, they are expressed more frequently in males than in females. XX x X’Y where X’=allele for white eye X X’ X’ X X X’ X Y X Y X Y Summary of Results PARENTS (Female: +) x (Male: W) OFFSPRING Phenotype Female: + Number 5016 Mal