Answer:
One parent is hybrid, one is recessive
Explanation:
If you do the punnet square, you will notice that there are two outcomes, and that they have a similar proportion, this is only possible if you math a recessive mouse (lets say the recessive allele is white), and a hybrid, that will show the dominant trait (lets say that black is dominant).
So: P=black and p=white
Pp x pp=
2/4 Pp(looks black) and 2/4 pp (looks white)
