Blend, or Both?

You'll learnhow a heterozygote can blend, show both alleles, or mask one, and how to tell these apart.

Cross a red snapdragon with a white one and the offspring is pink; cross a red bull with a white cow and the calf is roan — red hairs and white hairs, no pink anywhere. Same heterozygote, two completely different answers, and telling them apart on sight is most of this topic. Twelve short steps; press Next for each one.

AP BIOLOGY · 12 STEPS · 6 QUICK CHECKS · INCOMPLETE DOMINANCE = ONE BLEND · CODOMINANCE = BOTH, UNMIXED · v5

RR × WW · one new colour, or both old ones? · blend or both

Before you start

What you're looking at

A cross of a true-breeding red snapdragon (RR) with a true-breeding white one (WW), written R and W because neither allele masks the other.

The question

The offspring is pink, not red; which of Mendel's assumptions has this gene broken?

Step 1 / 12