HMB265H1 Chapter Notes - Chapter 4-5: Zygosity, Abo Blood Group System, Epistasis

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Naomi Levy-Strumpf, Stephen Wright

Document Summary

Generation times are long and families are relatively small (ie. statistical analysis is difficult) No pure-breeding lines and no controlled matings. Rarely a true f2 generation because brothers and sisters almost never mate. Pattern of inheritance is vertical at least one member in each generation has the disease. Especially when the disease is rare in a population, a vertical pattern is strong evidence that a dominant allele causes the trait. The alternative may unrelated people carry a rare recessive allele (chances of this is very low) Most single-gene diseases in humans are recessive most deleterious dominant alleles are unlikely to be transmitted to the next generation (except late-onset traits) Pattern of inheritance is horizontal unaffected parents are heterozygous carriers. Can be vertical if the recessive trait is extremely common in the population. Pages 36-45 extensions to mendel for single-gene inheritance.