Hypernyms (to doodle is one way to...): draw (represent by making a drawing of, as with a pencil, chalk, etc. on a surface). Doodle entails doing...: delineate; describe; draw; line; trace (make a mark or lines on a surface).
DNA polymerases can only extend a DNA strand in a 5â² to 3â² direction, different mechanisms are used to copy the antiparallel strands of the double helix. In this way, the base on the old strand dictates which base appears on the new strand.
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.