Polydactylism occurs a. only in cats b. only in humans c. in less than one in 1000 children d. more commonly in certain populations, such as the amish

D. more commonly in certain populations, such as the Amish. Their allele frequency or "gene pool" is smaller since Amish people tend to marry other Amish people, so certain genes, such as polydactylism, get passed around quite often amongst their confined population.

The answer would be D. Because it is commonly found in Humans and Animals and amish are around animals all the time.

Ithink option a is correct because you cannot donate a different blood group than yours because it won't match.option a says betsy can donate to mark. they have the same blood group so donation can happen.

The correct answer is d