If a high concentration of a particular nucleotide lacking a hydroxyl group at the 3ʹ end is added to a PCR reaction,
A) a strand containing that nucleotide will cease to elongate.
B) strand elongation will proceed as normal.
C) nucleotides will be added only at the 5ʹ end.
D) Thermus aquaticus DNA polymerase will become nonfunctional.
E) the primer will be unable to anneal with the DNA template.

Question

Quizplus · Accepted Answer

PCR relies on the ability of DNA polymerase to add nucleotides to the 3ʹ end of the growing strand. If a nucleotide lacking a hydroxyl group at the 3ʹ end is added to the reaction, the growing strand will not be able to continue elongation, as it requires a free 3ʹ hydroxyl group to form a phosphodiester bond with the next nucleotide. Therefore, choice A is the best answer.

If a High Concentration of a Particular Nucleotide Lacking a Hydroxyl