[Campbell Biology P.445] According to the diagram in Concept 18.3, which of the following is... | Practice Question

According to the diagram in Concept 18.3, which of the following is a role of noncoding RNAs in controlling gene expression?

  • A: Promoting heterochromatin formation to block transcription.
  • B: Directly synthesizing proteins from mRNA.
  • C: Repairing damaged DNA strands.
  • D: Increasing the rate of mRNA transcription.

Explanation

The diagram under 'Chromatin modification' clearly states that 'Small and/or large noncoding RNAs can promote heterochromatin formation in certain regions, which can block transcription.' This directly supports option A.