[Campbell Biology P.391] In the context of bacterial transcription, which of the following s... | Practice Question

In the context of bacterial transcription, which of the following statements accurately describes the relationship between a promoter, a terminator, and a transcription unit?

  • A: The terminator is located upstream of the promoter, and both are within the transcription unit.
  • B: The promoter is downstream from the terminator, and the transcription unit includes only the coding sequence.
  • C: The promoter is upstream from the transcription unit, which extends downstream to include the terminator.
  • D: Both the promoter and terminator sequences are translated into protein.

Explanation

The text defines the promoter as the DNA sequence where RNA polymerase attaches and initiates transcription. It states that the promoter is 'upstream from the terminator.' The 'transcription unit' is defined as 'The stretch of DNA downstream from the promoter that is transcribed into an RNA molecule.' This implies the transcription unit starts at or immediately after the promoter and extends to include the terminator, which signals the end of transcription.