There are cases in which a person inherits a very high susceptibility to cancer. A woman who is heterozygous for a mutation in the BRCA1 gene has one functional allele that helps to suppress tumor formation and one nonfunctional allele of the same gene
She has a 50-70%
chance of developing breast cancer before age 70. A tumor is likely to form when a cell
"loses heterozygosity" at the BRCA1 gene. This will happen if:
A. germ cells in the affected individual
develop a mutation in the remaining
functional allele of BRCA1.
B. a somatic mutation in a breast cell
inactivates the remaining functional BRCA1
allele.
C. a silent mutation occurs in the remaining
functional BRCA1 allele.
B
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a. true b. false
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