What is the Difference Between the Leading Strand and the Lagging

Question

What is the difference between the leading strand and the lagging strand in DNA replication?
A)The leading strand is synthesized in the 3' → 5' direction in a discontinuous fashion, while the lagging strand is synthesized in the 5'→ 3' direction in a continuous fashion.
B)The leading strand is synthesized continuously in the 5'→ 3' direction, while the lagging strand is synthesized discontinuously in the 5'→ 3' direction.
C)The leading strand requires an RNA primer, whereas the lagging strand does not.
D)There are different DNA polymerases involved in elongation of the leading strand and the lagging strand.
E)The leading strand is synthesized in the 3' → 5' direction in a continuous fashion, while the lagging strand is synthesized in the 5'→ 3' direction in a discontinuous fashion.

Accepted Answer

The leading strand is synthesized continuously in the 5'→ 3' direction, while the lagging strand is synthesized discontinuously in the 5'→ 3' direction. This is because DNA synthesis can only occur in the 5'→ 3' direction, so the leading strand can be continuously synthesized in the same direction as the replication fork moves, while the lagging strand must be synthesized in smaller fragments (Okazaki fragments) in the opposite direction and then joined together later.