What is formed on the lagging strand during DNA replication?

During DNA replication, the lagging strand is synthesized discontinuously, resulting in the formation of short segments known as Okazaki fragments. These fragments occur because DNA polymerase can only synthesize DNA in the 5' to 3' direction. On the lagging strand, as the replication fork opens up, new sections of DNA are synthesized in short bursts, creating these discrete fragments.

Each Okazaki fragment is initiated by a short RNA primer, which provides a free 3' hydroxyl group for DNA polymerase to add nucleotides. As the replication process continues, the RNA primers are later removed and replaced with DNA, and the fragments are then connected by the enzyme DNA ligase, helping to form a continuous strand.

The other terms mentioned relate to different aspects of DNA replication or structure: nucleotide pairs refer to the complementary bases that bond together in double-stranded DNA, primer sequences signify the short RNA segments that initiate DNA synthesis, and DNA helicase is the enzyme responsible for unwinding the double helix to allow replication to proceed. However, only the Okazaki fragments are specific to the lagging strand during the DNA replication process.