If both parents are heterozygous (Mm) in genotype (pigmented
in phenotype):
- Due to meiosis,
1/2 of both eggs and sperm are dominant (M), 1/2 are recessive (m).
- Offspring genotype ratio is 1 MM : 2 Mm : 1 mm.
- Offspring phenotype ratio is 3 pigmented
: 1 albino.
Note these ratios are based on probability, assuming random fertilization of gametes.
- Assuming brown eyes (B) is dominant over blue eyes (b), can 2 brown-eyed parents have a baby with blue eyes?
- Yes if the parents are heterozygous; 1/4 of their offspring will be blue-eyed.
