ratios of genetics

heterozygous x heterozygous (monohybrid)

3:1 — dominant to recessive (complete dominance & separate chromosomes)

carrier female x affected male (colorblindness)

2:2 affected to normal

• 1 girl = affected, 1 = carrier

• 1 boy = affected, 1 = normal

heterozygous x heterozygous (dihybrid & separate chromosomes)

9:3:3:1 - 4 possible gametes

heterozygous x heterozygous (dihybrid & same chromosomes)

3:1 - 2 possible gametes

white x red (incomplete dominance, monohybrid)

1:2:1

red x white (codominance)

1:2:1

how do you determine number of different gametes

2^n —- n = # heterozygous genotypes