A recessive allele, such as the allele for white flower color in pea plants, affects an individual's phenotype only when
A) both parents have one copy of the recessive allele.
B) the individual inherits only one allele.
C) it is present on both chromosomes.
D) it is absent from both chromosomes.

Question

Quizplus · Accepted Answer

A recessive allele only affects an individual's phenotype when it is present on both chromosomes (homozygous recessive). In the case of pea plants, a white flower color phenotype is expressed only when both alleles for flower color are "w" (recessive). Therefore, this answer choice is the best option.

A Recessive Allele, Such as the Allele for White Flower