Question

Incomplete Dominance—Predicting Flower Color in Snapdragons

Snapdragons are popular garden plants that produce brightly colored flowers. When a plant that is homozygous for white flowers is crossed with a plant that is homozygous for red flowers, all offspring are pink. Snapdragons are an example of a plant that exhibits an inheritance pattern called incomplete dominance.


Determine the genotype of each parent plant and write them below.

Use W to indicate the allele for white flowers and R to indicate the allele for red flowers.
Genotype of homozygous parent plant with white flowers: _____
Genotype of homozygous parent plant with red flowers: _______

Answer 1

For the homozygous parent for the white flower, it'd be either WW or ww, it just depends on if the genotype is homozygous dominant or homozygous recessive. As for the red parent plant it'd be the same either RR or rr, it's just depends on if it's homozygous dominant or homozygous recessive.

Answer 2

Genotype of homozygous parent plant with white flowers: WW.

Genotype of homozygous parent plant with red flowers: rr.

In a Punnet square, the rule says that a dominant allele is write with a capital letter. The recesive allele is write with a lower case letter.

Homozygous means that the two forms of the allele are the same. So, having that in mind, homozygous dominant : WW. homozygous recesive: rr