Which of the following would be true of a plant heterozygous for a single gene controlling flower color? (Assume complete dominance).

If crossed with another heterozygous plant, the majority of progeny will have the dominant flower color.

If crossed with another heterozygous plant, the majority of progeny will have the dominant flower color.

Explanation:

If you cross a dominant heterozygous plant with a single gene with another heterozygous plant, because of the dominance effect in the heterozygous plant, the phenotype is affected and because dominance makes it difficult to distinguish between a homozygous and heterozygous plant, the heterozygous dominant plant in this case will act like a homozygous parent and hence the majority of progeny will have dominant flower color.