Question

4)What is the reason for the discontinuous synthesis of DNA on one of the parental strands?

Answer 1

Dear student,

Synthesis of DNA always takes place in 5'→3' direction.

In a double stranded DNA both strands are anti parallel and complementary, thus only one strand (i.e.,3'→5') can synthesize complementary strand in 5'→3' direction.

The other strand also known as lagging strand, (i.e.. 5'→3' ) has to be synthesised in small stretches in opposite direction. These are called Okazaki fragments. That is why DNA synthesis is discontinuous on one of the parental strands of DNA.

The Okazaki fragments are joined together by DNA ligase enzyme that closes the nicks.

Regards