Answer: alleles
Explanation:
"An allele is a variant form of a gene. Genes come in different varieties, called alleles. Somatic cells contain two alleles for every gene, with one allele provided by each parent of an organism."- Nature .com
I think it’s a, hopefully you get it right!
We need to know the dominant and recessive traits of the noombats in order to answer this question. If both of them has yellow as the dominant trait, then green may be recessive. In that case there is a chance for them to have a green bellied child. Its impossible to tell the percentage though because we don't know enough about the animals.
