Question

What is the reason for the difference in the synthesis of the leading and lagging strands of DNA molecules?

      
A. DNA polymerase can join new nucleotides only to the 3' end of the growing strand.

       
B. One strand must be completely synthesized before synthesis of the next can begin.

       
C. Helicase and SSB proteins work only at the 5' end of the chromosome.

       
D. DNA ligase only works in the 3' to 5' direction

       
E. The origins of replication occur only at the 5' end of the chromosome.

Answer 1

Option-A- DNA Polymerase can join new nucleotides only to the 3' end of the growing strand.

DNA Polymerase is the enzyme that adds nucleotides to the growing daughter strand. It can add nucleotides only in the growing strand which is in the 5'to 3' direction and elongate it continuously which is called as leading strand. On the other strand, DNA is synthesised in fragments called as Okasaki fragments which is then ligated by DNA ligase.

The other options are not correct.