The occurrence of which event(s) usually does not lead to an undercounting of the real number of substitutions?

Question

Quizplus · Accepted Answer

Single substitutions involve only one nucleotide substitution at a time and do not have the potential for hiding or masking other substitutions, thus making it unlikely for undercounting to occur. Parallel substitutions (A) and coincident substitutions (E) involve multiple substitutions occurring at the same time, which can hide or mask each other and potentially lead to undercounting. Back substitutions (B) involve reversing a previous substitution, so they do not add any new substitutions to the count. Multiple substitutions (D) involve more than one nucleotide substitution at the same site, which can also result in undercounting.

The Occurrence of Which Event(s) Usually Does Not Lead to an Undercounting