Question

in a group of fruit flies, some individuals have a gray body and others have a black body. in this group, the gene for the body color trait has two alleles. the allele b is for a gray body, and the allele b is for a black body. a certain fruit fly from this group has a gray body. this fly has one allele for a gray body and one allele for a black body. based on this information, what is this fruit fly’s phenotype for the body color trait?\
options: bb, bb, a gray body, a black body

Explanation:

Step1: Recall Phenotype Definition

Phenotype is the observable trait (physical characteristic) of an organism, determined by its genotype (alleles).

Step2: Analyze Given Alleles

The fruit fly has one allele for gray body (\(B\)) and one for black body (\(b\)), so its genotype is \(Bb\).

Step3: Determine Phenotype from Genotype

The allele \(B\) (gray body) and \(b\) (black body) – since \(B\) is for gray and the fly has \(B\) (even with \(b\)), the observable trait (phenotype) is gray body.

Answer:

a gray body