Answer: The alleles of a plant that is heterozygous for seed color can be represented as Y for dominant allele for yellow seed and y for recessive allele for green seed.
Explanation: A plant that is heterozygous for seed colour has one dominant allele and one recessive allele for seed colour. If Y represents the dominant allele for yellow seed colour and y represents the recessive allele for green seed colour, therefore the plant has a genotype of Yy. A dominant allele is one that has the ability to mask the effect of a recessive allele while a recessive allele is one whose effect is masked by a dominant allele. Dominant alleles are denoted with upper cases while recessive alleles are denoted with lower cases. A plant that is heterozygous for seed colour with genotype Yy will manifest outwardly as Yellow seed colour due to the presence of the dominant allele Y.