Question

During DNA replication, Okazaki fragments are used to elongate

• A. The leading strand towards replication fork
• B. The lagging strand towards replication fork
• C. The leading strand away from replication fork
• D. The lagging strand away from the replication fork

Answer 1

The Correct Option is D

 During the process of DNA replication, the two strands of DNA separate, allowing each strand to serve as a template for the formation of a new complementary strand. DNA replication involves both leading and lagging strands, which are replicated slightly differently due to the directional nature of DNA polymerase enzymes.

The DNA polymerase enzyme can only add nucleotides in the 5' to 3' direction. As a result, the leading strand is synthesized continuously as it moves towards the replication fork. However, the lagging strand, which runs in the opposite 3' to 5' direction, must be replicated in small sections called Okazaki fragments. These fragments are synthesized discontinuously, moving away from the replication fork, and are later joined together by the enzyme DNA ligase to form a continuous strand.

Given the options:

The leading strand towards replication fork

The lagging strand towards replication fork

The leading strand away from replication fork

The lagging strand away from the replication fork

The correct answer is

The lagging strand away from the replication fork

, as Okazaki fragments are used for replication of the lagging strand in the direction away from the replication fork.

 

To summarize, Okazaki fragments are necessary for the synthesis of the lagging strand, which is synthesized in short segments. This synthesis occurs discontinuously and results in fragments that are subsequently connected to form a complete, continuous strand of newly synthesized DNA.