The polymerization of deoxynucleotides is catalyzed by :
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → DNA polymerase
In DNA replication, a new DNA strand is built by joining deoxynucleotides one after another, using the old strand as a template. The main enzyme for this is DNA-dependent DNA polymerase. It is so named because it uses a DNA template to make DNA. It is very efficient and joins a large number of nucleotides in a very short time.
(1) DNA polymerase — Correct. It catalyses the polymerisation of deoxynucleotides on a DNA template.
(2) RNA polymerase — Incorrect. RNA polymerase makes RNA from ribonucleotides during transcription. It does not make DNA.
(3) DNA ligase — Incorrect. DNA ligase does not build a strand. It only joins pieces of DNA, such as the short Okazaki fragments of the lagging strand.
(4) Topoisomerases — Incorrect. Topoisomerases help to relieve the twisting (supercoiling) of DNA. They do not add nucleotides.
NCERT Extract:
The Machinery and the Enzymes – …
