21.Which ofthe following is NOT required for a polymerase chain reaction (PCR) using a thermophilic DNA polymerase?
(A) A DNA template
(B) ATP
(C) A primer
(D) Four 2'-deoxynucleoside triphosphates (dNTPs) or their analogues
(E) Magnesium or manganese ions

正確答案為 (B) ATP 考點：PCR...