lecture 19 - extensions to mendel

• What does the multiplication rule state regarding probability?

  To determine the probability of two events happening, multiply their individual probabilities.
• What does the addition rule state regarding probability?

  To determine the probability of one of two mutually exclusive events (only one occurs) occurring, add their individual probabilities.
• What are the three alleles for the ABO blood groups and their corresponding carbohydrates?

  • Allele A: adds galactosamine
  • Allele B: adds galactose
  • Allele i: does not add sugar
• What is co-dominance in genetics?

  • When the heterozygote shows some aspect of the phenotype of both homozygotes.
• What is the key idea regarding allele segregation?

  • If alleles are on separate chromosomes, solve for each gene separately.
  • The probability of having AaBBCC offspring is the product of the probabilities of having Aa, BB, and CC offspring.
• What is incomplete dominance in genetics?


  The phenotype of the heterozygote is intermediate between the two homozygotes.
• Pleiotropy


  1 single gene controls multiple traits
• Sickle Cell Anemia & Pleiotropy

  The inherited red blood cell disorder causes multiple pleiotropic phenotypes like resistance to malaria, vascular damage, diseased red blood cells.
• Polygenic Inheritance


  Multiple genes control a single trait
• Height & Polygenic Inheritance


  Differences in height across population caused by polygenic inheritance. Our geness from parents influence our singular height trait