Question

Choose the correct answer from the alternatives given :
Discontinuous synthesis of DNA occurs in one strand, because

• A. DNA molecule being synthesised is very long
• B. DNA dependent DNA polymearse catalyses polymerisation only in one direction (5 $\to$ 3)
• C. It is a more efficient process
• D. DNA ligase has to have a role

Answer 1

The correct option is B DNA dependent DNA polymearse catalyses polymerisation only in one direction (5 $\to$ 3)

The DNA-dependent DNA polymerases catalyze polymerization only in the one direction, that is 5 →→ 3. This creates some additional complications at the replicating fork. Consequently, on one strand (the template with polarity 3 →→ 5), the replication is continuous, while on the other (the template with polarity 5 →→ 3), it is discontinuous. The discontinuously synthesizing fragments are later joined by the enzyme DNA ligase.

So, the correct answer is 'DNA dependent DNA polymerase catalyses polymerisation only in one direction (5 → 3)'.