A geneticist wishes to determine if a red rose of a certain variety is homozygous for the color red.

If red is dominant over white, the red rose should be cross-pollinated with roses of the same variety that are:

A) homozygous red.

B) homozygous white.

C) heterozygous red.

D) heterozygous pink.

B

Explanation:

1. As given, Red is dominant on white.

And a geneticist wants to determine that red rose of certain variety is homozygous for the red color.

2. Here if red is crossed with pure red, the geneticist can not determine the red gene if it is dominant or recessive.

3. So, the red rose should be cross-pollinated with roses of same variety that are homozygous white.

Finally the answer is B (homozygous white).