Match List-I with List-II
| List-I | List-II |
|---|---|
| Enzymes/term | Functions |
| (A) DNA ligase | (I) Joining of discontinuously synthesised fragments of DNA |
| (B) RNA polymerase | (II) Catalyses the polymerisation of DNA in only one direction |
| (C) DNA-dependent DNA polymerase | (III) Provides energy for polymerisation reaction |
| (D) Deoxyribonucleoside triphosphate | (IV) Binds to the promoter and initiates transcription |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A) - (I), (B) - (IV), (C) - (II), (D) - (III)
(A) DNA ligase — this matches (I) Joining of discontinuously synthesised fragments of DNA. On one strand, DNA is made as small pieces (Okazaki fragments). DNA ligase joins these pieces into one continuous strand.
(B) RNA polymerase — this matches (IV) Binds to the promoter and initiates transcription. RNA polymerase attaches at the promoter of a transcription unit and starts making RNA from the DNA template.
(C) DNA-dependent DNA polymerase — this matches (II) Catalyses the polymerisation of DNA in only one direction. It adds nucleotides only in the 5′ → 3′ direction. This is why one strand is made continuously and the other in fragments.
(D) Deoxyribonucleoside triphosphate — this matches (III) Provides energy for polymerisation reaction. These molecules do two jobs. They are the building blocks (substrates) of the new DNA, and when their two extra phosphates are removed, they give the energy for the reaction.