You first have to figure out the genotypes of the parents. From the question, we can infer that one of the parent is hetero_zygous while the other is homo_zygous recessive.
Crossing them over will produce a punnet square that looks something like this:
A a
a Aa aa
The genotypic ratio would be:
Aa : aa
50 : 50
The phenotypic ratio would be:
yellow : green
50 : 50
//
It doesn't allow me to use those words because apparently, it's inappropriate. Smh. It's literally biology terms.
