Fruit color in eggplants is controlled by the amount of a particular enzyme present. two copies of the purple allele produce enough enzyme to show the typical dark purple color in eggplants. one copy of the purple allele and one copy of the white allele results in a lighter shade called violet. two copies of the white allele does not produce any enzyme, which results in a white eggplant. which punnett square represents the cross of two heterozygous plants?