Question

name jarretpractice problems: sex linked genes*in fruit flies, eye color is a sex-linked trait. red is dominant to white *1. what are the sexes and eye colors of flies with the following genotypes:$x^r x^r$ _____$x^r x^r$ ___$x^r y$ ___$x^r y$ ___$x^r x^r$ _____these flies:

Explanation:

Step1: Identify sex from chromosomes

Females have two X chromosomes; males have X and Y.

Step2: Determine eye color (dominant $R$ = red, recessive $r$ = white)

For females: dominant $R$ masks recessive $r$; males only have one X allele, so it is expressed directly.

For $X^R X^r$:

Female, has dominant $R$ → red eyes

For $X^R Y$:

Male, has dominant $R$ → red eyes

For $X^r X^r$:

Female, only recessive $r$ → white eyes

For $X^R X^R$:

Female, only dominant $R$ → red eyes

For $X^r Y$:

Male, only recessive $r$ → white eyes

Answer:

$X^R X^r$: Female, red eyes
$X^R Y$: Male, red eyes
$X^r X^r$: Female, white eyes
$X^R X^R$: Female, red eyes
$X^r Y$: Male, white eyes