Question

Match List - I with List - II. 

Choose the correct answer from the options given below : 
 

• A. A-III, B-IV, C-I, D-II
• B. A-I, B-II, C-III, D-IV
• C. A-II, B-III, C-IV, D-I
• D. A-IV, B-I, C-II, D-III

Hint:

To avoid confusion between polymerases: DNA Pol III is the main workhorse for replication in E.coli. DNA Pol I is specifically for 'gap filling' and 'primer removal' due to its unique 5'\(\rightarrow\)3' exonuclease capability.

Answer 1

The Correct Option is C

Step 1: Concept:
The question tests the fundamental biochemical functions of vital enzymes used heavily in molecular biology and recombinant DNA technology.

Step 2: Step-by-step Explanation:

• A. DNA Ligase: This enzyme facilitates the joining of DNA strands together by catalyzing the formation of a critical phosphodiester bond. It essentially acts as molecular glue to seal nicks or join Okazaki fragments.
Therefore, A correctly pairs with II.

• B. Reverse Transcriptase: This is an RNA-dependent DNA polymerase uniquely found in retroviruses (like HIV). It utilizes a single-stranded RNA template to synthesize a complementary DNA (cDNA) strand.
Therefore, B correctly pairs with III.

• C. DNA polymerase I (E.coli): Discovered by Arthur Kornberg, this enzyme possesses 5'\(\rightarrow\)3' polymerase activity alongside a unique 5'\(\rightarrow\)3' exonuclease activity. In vivo, its primary role is to remove RNA primers and fill in the resultant gaps with DNA nucleotides during replication.
Therefore, C correctly pairs with IV.

• D. Type II restriction endonucleases: These are standard molecular scissors that recognize highly specific, short palindromic nucleotide sequences in double-stranded DNA and cleave the phosphodiester backbone at defined positions within or near that specific sequence.
Therefore, D correctly pairs with I.

• Combining these logic derivations gives the sequence A-II, B-III, C-IV, D-I.

Step 3: Final Answer:
The matched sequence clearly identifies Option (C) as the correct choice.