During which stage of DNA replication are Okazaki fragments formed?

Okazaki fragments are formed during the synthesis of the lagging strand in DNA replication. The lagging strand is synthesized in a discontinuous manner, which is necessary because DNA polymerase can only add nucleotides to an existing strand in a 5' to 3' direction. As a result, on the lagging strand, nucleotides are added in short segments, known as Okazaki fragments, away from the replication fork.

Since DNA replication involves unwinding the double helix, the leading strand can be synthesized continuously towards the fork, while the lagging strand must be synthesized in pieces. Each Okazaki fragment starts with an RNA primer that provides a starting point for DNA synthesis. Following this, the fragments must be joined together by the enzyme DNA ligase after their synthesis is complete.

Understanding the formation of Okazaki fragments is crucial for grasping how lagging strand synthesis differs from leading strand synthesis during DNA replication.