Human Growth and Development / Unit 2 HGD 0158 short lesson, about 20 seconds
Dominant and Recessive
Captions available
The idea
A dominant allele shows its effect with one copy; a recessive allele shows only with two copies, as blue eyes do.
In practice
Two heterozygous parents: a quarter of children homozygous brown, half heterozygous, a quarter blue-eyed.
Where people slip
Homozygous means the same allele from both parents; heterozygous means two different alleles.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Something wrong in this lesson? Flag it · Sources for Human Growth and Development