1. Pedigree Charts

2. Definitions Pedigree: the recorded ancestry of an individual (family tree). Pedigree Chart: a graphic presentation of a family tree that permits patterns of inheritance to be followed for a single trait.

3. Pedigree Charts Symbols: MalesFemalesMating Identical Twins Fraternal Twins Affected Individuals Known Heterozygotes Roman numerals represent generations (I, II, III). Arabic numbers represent individuals within a generation. Birth Order: left to right – oldest to youngest

4. Pedigree Charts Example: S – short-sighted s - normal vision I II III 1 2 1 1 2 34 5 6 2 3 4 5 6 SsSsss SsSs SsSs SsSs SsSs

5. hemophilia has been studied through pedigree charts traced back to a spontaneous mutation in Queen Victoria in the 1800’s. as royal families intermarried, the mutation spread quickly throughout the European royal families

6. Let H = normal h = hemophilia XHXhXHXh XHYXHY XHYXHYXhYXhYXHXHXHXH XHXhXHXh or XHYXHY XHXhXHXh XHXhXHXh

7. Homework