Question

Which two statements are true for the leading strand in DNA?

Answer 1

Answer: The correct options are statement first and fourth that is -

It is synthesized toward the replication fork and it is synthesized in the 5′ to 3′ direction.

Leading strand in DNA is the strand of new DNA being synthesized in the same direction where the replication fork is moving. The movement of replication fork allows the access of template for the new DNA.

The DNA synthesis is continuous in the leading strand. It is synthesized in the 5' to 3' as DNA synthesis always takes place in this direction. This is because dNTP ( deoxyribonucleoside triphosphate) provides free 3' OH group where new dNTP can be added by the enzyme DNA polymerase.

Answer 2

The correct answer is option A and D, It is synthesized toward the replication fork and It is synthesized toward the replication fork.

Reason -

A leading stand of DNA is synthesized in the direction same as that of the replication fork movement. Since the replication moves in the 5’-3’direction, the leading strand of DNA is also synthesized in the 5’-3’direction. This strand is a continuous strand and it has no breaks in it. The nucleotides are continuously added to the 3’ end of the strand.