How to Differentiate Between Poisonous Snakes and Non Poisonous Snakes. Some snakes harm their prey by injecting venom through their fangs; some of this venom can be harmful to humans, resulting in what we often think of as poisoning...
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.
The mechanism of transcription has parallels in that of DNA replication. As with DNA replication, partial unwinding of the double helix must occur before transcription can take place, and it is the RNA polymerase enzymes that catalyze this process.ranscription is the process by which DNA is copied (transcribed) to mRNA, which carries the information needed for protein synthesis. Transcription takes place in two broad steps. First, pre-messenger RNA is formed, with the involvement of RNA polymerase enzymes.