Final answer:
DNA replication and RNA transcription share several steps, but unlike DNA replication, RNA transcription does not require a primer for initiation. The correct option is A) a requirement for a primer
Step-by-step explanation:
The initiation of DNA replication and RNA transcription indeed share several common features including the directionality of synthesis (5′3′), the unzipping or separation of the DNA strands, base-pairing of complementary nucleotides with the template strand, and the use of energy from triphosphate nucleotides. However, they differ in that DNA replication requires a primer to begin the synthesis of a new strand, while RNA transcription does not.
In DNA replication, an enzyme called RNA primase synthesizes a short RNA primer, which provides the necessary 3′-OH group that DNA polymerase can extend by adding nucleotide triphosphates. In contrast, RNA polymerase can initiate RNA synthesis de novo, without a primer. This is because the synthesis of a new strand of RNA by RNA polymerase does not require the free 3′-OH end that DNA polymerase needs when synthesizing DNA.
Therefore, the characteristic that does NOT occur in both DNA replication and RNA transcription processes is A) a requirement for a primer. The correct option is A) a requirement for a primer