Recessive genes are usually expressed in humans only when ________.
A) the organism is in the embryonic stage
B) they are coding for skin color
C) they are coding for genetic diseases
D) both alleles are exactly the same, or homozygous

Question

Quizplus · Accepted Answer

Recessive genes are expressed only when both alleles, or gene copies, are exactly the same, meaning the individual is homozygous for that trait. If the individual is heterozygous, meaning they have one dominant and one recessive allele, the dominant allele will be expressed and mask the recessive allele. This is known as the principle of dominance in genetics. Recessive genes can code for traits such as eye color or blood type, but they can also code for genetic diseases if the gene mutation is present in both alleles.

Recessive Genes Are Usually Expressed in Humans Only When ________