What is the net effect of a tautomeric shift event,and the subsequent replication required to segregate the mismatched base pair? 1.A:T to G:C base pair substitution
2)G:C to A:T base pair substitution
3)A:C to G:T base pair substitution
A) 1
B) 2
C) 3
D) 1 and 2
E) All of these

Question

Quizplus · Accepted Answer

A tautomeric shift event is a spontaneous change in the protonation pattern of a nucleotide base, leading to a change in its chemical structure, which can result in a mismatched base pair during DNA replication. The net effect of this event and subsequent replication is a base pair substitution, leading to a mutation in the DNA sequence.

Option 1 (A:T to G:C) and option 2 (G:C to A:T) both describe a transversion, where a purine base is replaced by a pyrimidine (or vice versa), leading to a change in the amino acid that is coded for by the affected codon.

Option 3 (A:C to G:T) describes a transition, where a purine is replaced by a different purine (or a pyrimidine is replaced by a different pyrimidine), which may or may not result in a change in the amino acid sequence.

Therefore, options 1 and 2 both result in a net effect of a base pair substitution, while option 3 may or may not have an effect on the amino acid sequence. Thus, the best choice is D (1 and 2).

What Is the Net Effect of a Tautomeric Shift Event,and