[Campbell Biology P.424] According to the provided text, which statement best describes a ke... | Practice Question

According to the provided text, which statement best describes a key difference in how coordinately controlled genes are typically organized and regulated in eukaryotes compared to bacteria?

  • A: In eukaryotes, co-expressed genes are usually clustered into operons, similar to bacteria.
  • B: Eukaryotic co-expressed genes are often scattered across different chromosomes, with coordinate control relying on common transcription activators.
  • C: Bacteria regulate co-expressed genes individually, while eukaryotes group them into single mRNA molecules.
  • D: Eukaryotic gene expression is exclusively regulated by steroid hormones, whereas bacterial regulation is solely via operons.
  • E: Eukaryotic coordinated control primarily depends on chromatin modification, which is absent in bacteria.

Explanation

The text explicitly states: 'Eukaryotic genes that are co-expressed... are typically scattered over different chromosomes. Here, coordinate gene expression depends on every gene of a dispersed group having a specific combination of control elements. Transcription activators in the nucleus that recognize the control elements bind to them, promoting simultaneous transcription of the genes, no matter where they are in the genome.' This directly supports option B and contrasts with the operon model in bacteria.