Which statement about cystic fibrosis is true? Cystic fibrosis affects a person's ability
to make normal red blood cells.

Cystic fibrosis is caused by a deletion of
one codon in the DNA molecule.

Cystic fibrosis is caused by a mutation in
which a dominant allele replaces a
recessive allele.

Carriers have an advantage over people
who do not have the cystic fibrosis
mutation