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Question
Cystic fibrosis (CF) is caused by a recessive allele. A child has CF, even though neither of his parents has CF. Which of the following describes the genotypes of the parents?
A) One is homozygous dominant for the CF gene, and the other is heterozygous.
B) One is homozygous recessive for the CF gene, and the other is heterozygous.
C) They are both homozygous recessive for the CF gene.
D) They are both homozygous dominant for the CF gene.
E) They are both heterozygous for the CF gene.
Answer
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Related questions
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Programmed cell death is also known as ________.
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