A Recessive Allele Can Only Appear in the Phenotype of an Individual

Question

A recessive allele can only appear in the phenotype of an individual
A)in the F1 generation.
B)exposed to certain environmental conditions.
C)who carries the mutation in his or her gametes.
D)who is homozygous for the mutation.

Accepted Answer

In order for a recessive allele to be expressed in the phenotype of an individual, the individual must be homozygous for the disorder. This means that they must carry two copies of the recessive allele. If an individual only carries one copy of the recessive allele, they are considered a carrier and will not exhibit the disorder. Additionally, the presence of a recessive allele in an individual's gametes (sperm or eggs) is not enough for it to be expressed in the phenotype. It must be homozygous for the allele in order for it to be expressed.