Question

Snapdragons are a type of flower. When red snapdragons are crossed with white snapdragons the resulting flowers are all pink. A scientist then crosses pink snapdragons with pink snapdragons. 100 offspring flowers and their colors are recorded. Of the 100 flowers counted, how many are likely pink?.

Answer 1

50% chance of the offspring having pink flowers.

Step-by-step explanation:

This is an example of "incomplete dominance," where both alleles contribute to the outcome. In some cases of incomplete dominance, both alleles might contribute equally so one allele would produce red pigment and the other white; thus, a pink plant appears.

If we were to cross a plant with pink flowers with a plant with white flowers, there would be a 50% chance of the offspring having pink flowers.

Here are the genotypes and phenotypes that we will use to solve this problem:

RR - red

RW - pink

WW - white

Since the first parent plant is pink, they would have the RW genotype. The other parent is white, so they would have the WW genotype. The 2 x 2 Punnett square below shows us the progeny that would be predicted from this cross.

RW x WW

We can see in the Punnett square that there is a 50% chance of the offspring having the RW genotype and thus the pink phenotype. We also see that there is also a 50% chance of the offspring having the WW genotype with the white phenotype.