Question

if a homozygous dominant parent and a homozygous recessive parent mate what is the probability they will have a heterozygous child

Answer 1

100%

Use a punnet square for an example, dominant homozygous on-top and recessive heterozygous on the left side.

In the square, the results are completely heterozygous and leave none for anything else or homozygous results.

Here’s an image to help; hope this helps!