Which of the following describes a non-sense mutation?
A.Base pair change results in a premature stop codon; protein is nonfunctional.

B.Base is changed but the resulting amino acid is the same as in the non mutant DNA. No outward changes
.
C.A base is either added or deleted and causes the codons to be read incorrectly.

D.Base pair change results in a different amino acid; this may or may not affect the protein that result.

Mutation, generally, refers to any change that occurs to the genetic sequence of a DNA. It can occur in different forms, hence, has different types. One particular type is the base pair substitution mutation, which involves the replacement of one or more nucleotide base by another in a sequence.

Base pair substitution can either result in one of the following namely: silent, missense, and nonsense. In NONSENSE mutation, the replacement of bases in the sequence causes the translation process to stop because a STOP CODON is prematurely encountered. Hence, the protein is non-functional.