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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Each offspring in Generation 2 has black fur. Use the drop-down menus to identify the genotypes of the offspring shown.



The genotypes of the offspring shown in Generation 2 are Select the correct option
BB, Select the correct option
bb, and Select the correct option
Bb.

Answer 1

Black is dominant (B) and white is recessive (b). The white mate is bb. Because all their offspring are black, the black parent must be homozygous BB (a Bb parent × bb would produce some white). A BB × bb cross yields only Bb offspring (black).

So the three Generation 2 offspring are: Bb, Bb, Bb.