how does the rna primer work in dna replication
DNA polymerases cannot initiate DNA synthesis - they can only add on to an existing strand of DNA or RNA. The existing strand is said to prime DNA synthesis. RNA polymerases, however, can begin copying a parent strand with no primer - just as they do in transcription of genes. During DNA replication, RNA primers are produced by RNA polymerases in order to provide a starting point for DNA polymerases to extend from.