The colour of eyes in fruit flies is determined by a gene on the X chromosome with two alleles.

I Need help to understand this question please help

1. The colour of eyes in fruit flies is determined by a gene on the X chromosome with two alleles.

    XR = red eyes;         Xr = white eyes

Cross a red eye male to a white eye female. Write out the Punnet square of the cross. 2 marks

2.
The colour of eyes in fruit flies is determined by a gene on the X chromosome with two alleles.

    XR = red eyes;         Xr = white eyes

Cross a red eye male to a white eye female. Write out the genotypes, phenotypes, and sex of the offspring. 2 marks

if someone could just explain it id be soo extremely happy thank you