Think about the dna coding sequence of a gene. if an a were swapped for a t, what kind of mutation could it cause and why?
a. it could cause a frameshift nonsense or frameshift missense mutation because it would change the reading frame of the codon triplet.
b. it could cause a nonsense mutation because the sequence would no longer be the same, so the protein would be shorter and non-functional.
c. it could cause a silent mutation because a and t are complementary to each other so it is not really a substitution mutation.
d. it could cause a silent, missense, or nonsense mutation because those are the types that can be caused by a nucleotide-pair substitution like this one.