Question

Consider the sex-linked inheritance patterns of a cross between two flies, a white-eyed female (XWX) and a red-

Answer 1

Red eyes are not gender specific and 100% of the offspring

would have red eyes would have red eyes if the gene were on autosome.

Explanation:

If the eye colour is not sex-linked and the traits are on the autosomes.

Genotype for male = XWY or XwY

Genotype for female = XWXW, XWXw. XwXw

Punnet square:

cross between red eye male and white eye male

         XW      Y    

XW XWXW  XWY

XW XWXW  XWY  all oofspring red eye

cross between white eye male and red eye female

           Xw      Y

XW   XWXw  XWY

Xw    XwXw  XwY      1 red male:1 white male: 1 red male : 1 white female

if mother has recessive gene all the male will be white eyed.

all the female progeny will have red eye because father had dominant red eye.

The red eye is dominant over white hence dominant trait will appear.

Answer 2

Answer: The correct answer is D. Red eyes are not gender specific. Depending on the genotype of the male fly, WW or Ww, either 100% or 50% of the offspring would have red eyes.

Explanation: