Final answer:
Okazaki fragments are short DNA segments on the lagging strand of DNA formed during replication, requiring RNA primers and are later joined by DNA ligase.
Step-by-step explanation:
Okazaki fragments are short stretches of DNA that are synthesized during DNA replication on the lagging strand. DNA replication occurs in the 5' to 3' direction, which means that while one strand - the leading strand - is replicated continuously towards the replication fork, the other strand - the lagging strand - is synthesized in the opposite direction, away from the fork. This results in the creation of the Okazaki fragments, which are then joined together by the enzyme DNA ligase, forming a continuous DNA strand.
The formation of Okazaki fragments begins with the unwinding of the parental DNA helix by helicase. This creates a replication fork with two strands, the leading strand and the lagging strand. As the fork progresses, primase synthesizes short RNA primers on the lagging strand. These primers are extended by DNA polymerase to form Okazaki fragments. Afterward, another DNA polymerase replaces the RNA primers with DNA, and DNA ligase seals the gaps between fragments to complete the replication process.