Question

A mutation that inserts or deletes one or two nucleotides is usually more harmful than a mutation that substitutes one base for another because —
A
it changes one amino acid in the sequence of a protein
B
it shifts the reading frame for the rest of the code causing many errors
C
the codon consists of three nucleotides coding for an amino acid
D
the chromosomes fail to separate resulting in trisomy 21

Answer 1

B

Inserting or deleting one or two nucleotides causes a frameshift mutation, which shifts the reading frame of the triplet codons and alters every amino acid downstream (often producing a nonfunctional protein).