- A DNA polymerase is unable to unwind the double helix without a primer present
- B DNA polymerase can only add nucleotides to an existing 3 prime OH end
- C Primers are required to supply the chemical energy needed for replication
- D Primers function to protect newly synthesized DNA strands from nucleases
Correct answer: B. DNA polymerase can only add nucleotides to an existing 3 prime OH end
Explanation: DNA polymerase cannot initiate synthesis on a bare template; it can only extend an existing strand with a free 3 prime OH, which the RNA primer provides.
Concept context
DNA structure, replication, transcription, translation, the genetic code, and gene regulation (lac operon). The single most important chapter for NEET molecular biology.