If green is dominant over purple, what is the genotype for a purple individual?

• A. homozygous dominant
• B. homozygous recessive
• C. heterozygous
• D. not applicable

Answer: (B)

When a trait is dominant, the phenotype you see is determined by having at least one dominant allele. Purple is the recessive color in this scenario, so purple only appears when both alleles are the recessive form. That makes the genotype homozygous recessive. If there were one dominant green allele and one recessive purple allele, the dominant green would mask the purple, yielding a green phenotype. If both alleles were the dominant green type, you’d also get green. So a purple individual must have two recessive alleles.