What causes one phenotype to be dominant and another recessive?

Question

What causes one phenotype to be dominant and another recessive?

In: 24

Answer 1

Generally a gene for a dominant trait does something, and for a recessive one doesn’t.

For example, a gene saying to put melanin in the iris of the eyes is going to be dominant- if you have one copy of it, you’ll put melanin in your irises and have brownish eyes. All you need is one gene to do that to make that work.