Question

RNA primer is removed by
A. DNAP-I
B. DNAP-II
C. DNAP-III
D. Primase

Answer 1

Hint: This is an enzyme which participates in the process of DNA replication of prokaryotes and this was initially characterized in E. coli.

Complete answer:
In living organisms, primers are short strands of RNA (ribonucleic acid). Primers are required for the synthesis of DNA because no other DNA polymerase is able to initiate polynucleotide synthesis. RNA primer is the RNA that initiates the synthesis of DNA. A primer is a short single stranded nucleic acid which is utilized by all the living organisms. The synthesis of a primer is important because the enzymes that synthesize DNA which are called as DNA polymerase can only attach new DNA nucleotides to an existing strand of nucleotides. The primers are removed before the replication of DNA completes and also because of the 5’ to 3’ exonuclease activity, DNA polymerase I removes RNA primers and this fills the gap between the Okazaki fragments of DNA. DNAP-II used for the repair of nucleotide base pairs. DNAP-III is responsible for the replicative DNA in E. coli. Primase produces RNA molecules and primers are synthesized by primase before DNA replication occurs.

Thus, the correct answer is option A. i.e., DNAP-I

Note: The primer serves to be prime and lay a foundation of DNA synthesis. In the laboratory, scientists can design and synthesize DNA primers with specific sequences in a single-stranded DNA molecule. These DNA primers are commonly used to perform polymerase chain reaction to copy pieces for DNA sequencing.