Question

which of the following descriptions is the best example of incomplete dominance.
(a) incomplete dominance contains only recessive traits
(b) incomplete dominance contains heterozygous alleles
(c) incomplete dominance contains only dominant traits
figure 11-12 incomplete
dominance in four o’clock plants, the
alleles for red and white flowers show
incomplete dominance. heterozygous
(rw) plants have pink flowers—a mix
of red and white coloring.

Explanation:

To determine the best example of incomplete dominance, we analyze each option:

• Option A: Incomplete dominance does not involve only recessive traits. Recessive traits are masked in complete dominance, but incomplete dominance shows a blend, so A is incorrect.
• Option B: In incomplete dominance, heterozygous (RW) individuals show a phenotype that is a blend of the two homozygous phenotypes (red - RR, white - WW). The example in the figure shows heterozygous (RW) plants with pink flowers (a mix of red and white), which matches the idea that incomplete dominance involves heterozygous alleles showing a blended trait.
• Option C: Incomplete dominance is not about only dominant traits; it's a blend, so C is incorrect.

Answer:

B. Incomplete dominance contains heterozygous alleles