The Covalent Extension of a Growing RNA Chain Takes Place

Question

The covalent extension of a growing RNA chain takes place in which of the following locations?
A) Promoter
B) Operator
C) Transcription bubble
D) Replication bubble
E) Enhancer

Accepted Answer

The extension of a growing RNA chain by the addition of nucleotides occurs during transcription, specifically within the transcription bubble. The promoter is the region where RNA polymerase binds to initiate transcription, and the operator is a region of DNA where a repressor protein can bind to prevent transcription. Replication bubble is related to DNA replication, and enhancer is a regulatory element that can influence transcription, but neither of these locations directly involve the covalent extension of an RNA chain.