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.



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



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From Generation 1, Offspring 4 mates with another white-furred black bear. What is the fur color probability in their offspring?


100% black fur


100% white fur


50% black fur and 50% white fur


75% black fur and 25% white fur

Answer 1

100% white fur.

Explanation: White fur is the recessive trait (bb). Offspring 4 is white, so its genotype is bb; the mate is also white (bb). A bb × bb cross produces only bb offspring, so all their cubs will have white fur.