Bob and Linda Are a Newly Married Couple

Multiple Choice

Bob and Linda are a newly married couple.They hope to have a child but are having trouble getting pregnant.They visit a fertility clinic,where they receive a variety of tests.One test shows that Bob is healthy but carries a single disease-causing allele for CFTR (the gene that can cause cystic fibrosis) ,but Linda does not.This means that

A) Bob's DNA sequence for CFTR is different from Linda's.
B) Bob has two different versions of the CFTR gene.
C) Linda does not have any copies of the CFTR gene.
D) Bob is unable to ever have children.
E) Both A and B