You have read that in guinea pigs, black fur is dominant to white fur. You are surprised then when your two white guinea pigs have all black F1.  When you cross the F1, you observe 9:7 black:white. How do you best explain this?

The color of sunflower pollen can be orange, yellow, or white-cream. Crosses reveal that true-breeding orange is dominant to both yellow and white-cream. However, a cross between true-breeding white-cream and yellow plants produced F1 plants with orange pollen. The F2 populations of this cross resulted in a ratio of nine orange: four white-cream: three yellow. What type of interaction do these results suggest?

Duchenne muscular dystrophy is caused by a recessive X-linked allele. A male with this disorder:

A pleiotropic gene

A cross between two short-tailed mice results in offspring in the ratio of 2/3 short-tailed and 1/3

In a plant species, if the B allele (blue flowers) and the b allele (white flowers) are incompletely dominant (Bb is light blue), what offspring ratio is expected in a cross between a blue-flowered plant and a white-flowered plant? 

If two Drosophila strains with the same autosomal recessive mutant phenotype of short bristles are crossed together and all the progeny are wild type, indicate which of the two possibilities below is correct.

If a mother has type A blood and their son has type O blood, what are the possible blood types of the father, if there are not additional genetic interactions occurring?

What possible genotype(s) could an individual of blood type B have? Select all that apply from the list below.