Question

The Great Smoky Mountains in Tennessee are home to American black bears. Most black bears have black fur, but in rare cases, black bears can have white or cream-colored fur.

A black-furred bear mates with another black-furred bear and produces four offspring. The offspring are all born on the same day in the same environment. The parents and offspring are shown.



image.png



When the offspring of Generation 1 become adults, Offspring 2 mates with a black bear with white fur. Their offspring are shown.



image.png



What causes white fur color in black bears?


nutrition


environment


recessive genes


dominant genes

Answer 1

Recessive genes.

Reason: Two black-furred parents produced a white offspring, which indicates the white trait is recessive (both parents can carry the recessive allele but show black because the black allele is dominant). Mating of white (homozygous recessive) bears produces white offspring, consistent with a recessive genetic trait rather than nutrition or environment.