In pea plants, round (R) seeds are dominant to wrinkled (r)…

In pea plants, round (R) seeds are dominant to wrinkled (r) seeds. A parent homozygous for round seeds is crossed with a parent homozygous for wrinkled seeds. If a plant from the F1 generation is backcrossed to the parent with wrinkled seeds, what is the proportion of the offspring that will have wrinkled seeds? (Assume 100% penetrance and complete dominance)

A recently found martian family is under study. According to…

A recently found martian family is under study. According to early studies, it was found that D (dextral) is dominant to d (sinistral). The mother and her brother, both have genotype Dd and are sinistral. The father of the family (not their father, but the mother’s husband) is dextral, with the genotype dd. All of their offspring are dextral. What best explains this event?