Help please, I don't understand how to do this.
Its about punnet squares and stuff

All 4 genotypes will be rr, and all 4 phenotypes will be white.

Explanation:

The "r" gene for white hair color is recessive, and both the bull and the cow have two copies of this gene. Therefore, since the "r" is the only gene that both could pass down, all offspring will have white hair and two copies of the "r" gene.

a time line cause it goes from 685 to 978