Tightly curled hair is caused by a dominant autosomal gene in humans. This trait is rare among northern Europeans. If a curly-haired northern European marries a person with straight hair, what phenotypes (and in what proportions) are expected in the offspring?

a.1/2 curly (because the curly-haired individgal is most likely heterozygous) 1/2 straight hair
b.1/2 curly (because the curly-haired individual is most likely homozygous), 1 /2 straight hair
c. all curly (because the curly-haired individual is most likely heterozygous)
d.3/4 curly (because the curly-haired individual is most likely heterozygous), 1/4 straight hair

Option A: 1/2 curly (because the curly-haired individual is most likely heterozygous) 1/2 straight hair

Explanation:

Tightly curled hair is caused by a dominant autosomal gene in humans, ca either be homozygous or heterozygous dominant.

A curly haired individual that is heterozygote crossed with a person with straight hair will produce 1/2 curly and 1/2 straight

        Cc (curly heterozygote)   x    cc (straight)

                                50%Cc and 50%cc

                                  1/2 curly and 1/2 straight

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