Question

How many dominant alleles I needed for an expression of a dominant phenotype

Answer 1

Hello,

The answer is "two".

Reason:

The number needed to have a dominate allies is two. You need two allies in order to have a relationship that helps form the genes and also the phenotype which is the physical features of a organism therefore the answer is two!

If you need anymore help feel free to ask me!

Hope this helps!

~Nonportrit

Answer 2

If the organism has regular dominance, It can be one or two because it could be homozygous dominant(AA) or heterozygous(Aa)
If the organism has incomplete dominance or co-dominance it can only be Homozygous Dominant (AA)