Question

17. Which of the following is not a characteristic of the transcriptional ground state in higher eukaryotes?

A. Gene promoters are essentially inactive in the absence of regulatory proteins.

B. RNA polymerase initiates efficient transcription in the absence of repressors.

C. Access to promoters is restricted by the structure of chromatin.

D. Virtually every gene requires activation.

18. Which of the following characteristics of eukaryotic gene expression regulation is also true in bacteria?

A. Posttranscriptional regulation is prominent because transcription is separated from translation in space and time.

B. Transcriptional activation is associated with changes in chromatin structure.

C. Many genes are regulated at the level of transcription initiation.

D. The transcriptional ground state is restrictive.

19. Efficiently translated mRNAs tend to be stable in the cytoplasm; those that are poorly translated tend to be rapidly degraded. Which of the following is not a step in the pathway for mRNA degradation?

A. targeting of upstream ORFs for nuclease binding

B. removal of the poly(A) tail

C. removal of the 5' 7-meG cap

D. binding of mRNA by 5'-3' and 3'-5' RNA exonucleases

20. Eukaryotic cells can regulate large sets of genes together by:

A. regulating ribosomal protein pre-mRNA splicing in the nucleus.

B. controlling mRNA stability.

C. controlling translational efficiency.

D. All of the choices are correct.