Question

In fruit flies, eye color is a sex-linked gene carried on the X chromosome. Red is dominant and white is recessive. Cross a male with red eyes with a female that has white eyes. Find the genotypes and phenotypes for each.

A. Male: X^RY, Female: X^WX^W, Genotype: X^RX^W, Phenotype: Red eyes
B. Male: X^RX^R, Female: X^WX^W, Genotype: X^RX^W, Phenotype: Pink eyes
C. Male: X^RX^W, Female: X^WX^W, Genotype: X^RW, Phenotype: Red eyes
D. Male: X^RY, Female: X^WX^W, Genotype: X^RW, Phenotype: Pink eyes

Answer 1

In fruit flies, eye colour is determined by a sex-linked gene on the X chromosome. A male with the red-eye phenotype crossed with a female with the white-eye phenotype produces different genotypes and phenotypes in their offspring. The genotypes and phenotypes of the offspring vary depending on whether the recessive trait is expressed by the male or the female.

Step-by-step explanation:

In fruit flies, eye colour is a sex-linked gene carried on the X chromosome. Red is dominant and white is recessive. When a male with red eyes (XRY) is crossed with a female that has white eyes (XWXW), the genotypes and phenotypes for each are as follows:

A. Male: XRY, Female: XWXW, Genotype: XRXW, Phenotype: Red eyes

B. Male: XRXR, Female: XWXW, Genotype: XRXW, Phenotype: Pink eyes

C. Male: XRXW, Female: XWXW, Genotype: XRXW, Phenotype: Red eyes

D. Male: XRY, Female: XWXW, Genotype: XRXW, Phenotype: Pink eyes