Final answer:
During DNA replication, the last nucleotide of the RNA primer is replaced by the DNA polymerase. This process involves the removal of the RNA primer, filling the gaps with DNA nucleotides, and sealing the nicks with DNA ligase.
Step-by-step explanation:
The last nucleotide of the RNA primer is replaced through a process called DNA replication. During replication, the RNA primer is first removed by the exonuclease activity of DNA polymerase. Then, the gaps left by the removal of RNA nucleotides are filled by DNA polymerase, which adds DNA nucleotides one-by-one. Finally, the nicks between the newly synthesized DNA and the previously synthesized DNA are sealed by DNA ligase, which forms phosphodiester linkages between nucleotides.