Final answer:
DNA replication involves the creation of a leading strand, which is synthesized continuously, and a lagging strand, which is synthesized in Okazaki fragments.
Step-by-step explanation:
During DNA replication, the DNA strand that is synthesized continuously towards the replication fork is known as the leading strand. However, the other strand, called the lagging strand, is synthesized in the opposite direction and must do so in short segments known as Okazaki fragments. This is because DNA polymerase can only synthesize DNA in the 5' to 3' direction. To replicate the lagging strand, the enzyme primase synthesizes short RNA primers, which are the starting points for the synthesis of the Okazaki fragments by DNA polymerase. After the fragments are formed, RNA primers are removed and replaced with DNA, and the fragments are then joined together by the enzyme DNA ligase to form a continuous strand.
As replication nears the end of a chromosome, the telomerase enzyme plays a crucial role in making sure that the lagging strand is properly completed, thus preventing the chromosome from progressively shortening during each cycle of cell division.