How are dominant genes written?

Question

How do you write a dominant gene?

Answer 1

I am not sure exactly what you are asking but I believe it may have to do with punnent square notation.

Capital letters are generally used to represent dominant genes and lower case letters to represent recessive genes.  The combination of these letter is known as a genotype.

When only one gene is involved there are three different possible genotypes

Aa - Heterozygous dominant

aa - Homozygous recessive

AA - Homozygous dominant