In Whitetail deer, there is a gene for coat color. Brown coats (B) are
dominant, and white coats (b) are recessive. If a homozygous dominant
buck was bred to a white-coated doe. What are all the possibilities (all the
phenotypes) their offspring will look like? What are the chances for
getting a brown deer?

All of the offspring are brown. The chances of getting a brown deer is 100%.

Explanation: The buck is homozygous dominant, meaning he has two of the brown (B) allele. The doe is white, and since the allele for a white coat is recessive, it has to have two white (b) alleles.

Set up a Punnett square with BB on one side and bb on the other. The results of this are 4 offspring all with the genotype Bb. Because brown (B) is dominant, all of them are brown.

To find the chance of getting a brown deer, take the number of brown deer (4) and divide it by the total number of outcomes (4). This gets you 4/4 or 1. As a percent, that would equal 100%.