Dominance and Punnett Squares

Draw

The ability in humans to roll the tongue is dominant (R) over the inability to do so (r). Complete a cross for two parents that are heterozygous for tongue rolling.

Draw

Complete the following cross; Hh x Hh. H=curly hair, h=straight hair. What is the percent chance of a straight haired child?

Draw

In flies, straight wings (D) are dominant to wrinkled wings (d). What are the genotypes of the 2 parents if 50% of the offspring have wrinkled wings.

Draw

In flies, straight wings (D) are dominant to wrinkled wings (d). What are the genotype and phenotype ratios of the following cross: DD x Dd

Draw

Incomplete dominance: Complete the Punnett square for a cross between a red and a pink flower. (RR x Rr) or (RR x RW)

Draw

Codominance: Complete the Punnett square for a cross between a red and white flower and a white flower. (Rr x rr) or (RW x WW)

Multiple Choice

In Andalusian chickens, feather color shows incomplete dominance. A black chicken (BB) is crossed with a white chicken (WW), producing blue-feathered offspring (BW). If two blue chickens are crossed, what percent of the offspring will have blue feathers?

• 100%
• 75%
• 50%
• 25%

Multiple Choice

In cows, coat color shows codominance. If a red cow (RR) is crossed with a white cow (WW), it will result in roan offspring (RW). If two roan cattle (RW) are crossed, what is the expected phenotypic ratio of the offspring?

• 1 red : 2 roan : 1 white

• 1 red : 1 white : 2 roan

• 2 red : 1 white : 1 roan

• 1 red : 3 roan