Question

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? 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? 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. it could cause a silent mutation because a and t are complementary to each other so it is not really a substitution mutation. it could cause a nonsense mutation because the sequence would no longer be the same, so the protein would be shorter and non-functional. it could cause a frameshift nonsense or frameshift missense mutation because it would change the reading frame of the codon triplet.

Answer 1

Hi, 

I think the answer you're looking for is already in the question you submitted. However, I disagree that a frameshift could result from the mutation because frameshifts would only happen if there were insertions or deletions in the sequence. For your question, this is an example of a simple point mutation/nucleotide base substitution, and would only result to either a missense or a nonsense mutation. Depending on the bases flanking your mutation, this results to transcribing a different sequence of RNA leading to translating either a different amino acid or a stop codon.