multiple allle inheritance

• • More than 2 alternative forms for particular gene
  • Remember 2 individuals can only have 2 alleles for each gene. This means higher number of possible genotypes and therefore phenotypes within a population
• Phenotypes

  • A blood group
  • B blood group
  • AB blood group

  Genotypes

  • A– I^A I^A or I^a i
  • B– I^B I^B or I^b i
  • AB– I^A I^B
  • O– ii
• • 3 different allele coding for 4 main blood groups in humans (A,B,AB and O)
  • both the IA allele for the A blood group and IB allele for the B blood group are dominant
• • The i allele for O is recessive
  • AB blood group example of co-dominance with both Ia allele and IB allele being expressed