Which is the following description about the carboxyl-terminal domain (CTD) in RNA polymerase II is NOT correct:
A. It binds to the mediator complex.
B. Its phosphorylation is related to the kinase activity of TFIIB.
C. The lack of CTD domain of RNA pol II would make the transcription not able to initiate.
D. The phosphorylation of its S5 site makes the change from initial polymerase form to elongation polymerase form.
E. The phosphorylation of its specific site will recruit many factors for RNA splicing and transcriptional termination.
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In the lac operon model, the trans-acting factor is___, and the cis-acting element is___
A. Repressor protein, lac O sequence
B. lac I gene, lac O sequence
C. Repressor protein, lac I gene
D. lac I gene, lac P gene
Which of the following statement is NOT true about the N terminal of histone and its modifications as well as its functions in nucleosome assembly:____
A. The N terminal of core histone contains several amino acid residues with positive charge, which can interact with DNA molecule and stabilize the nucleosomes.
B. The Ser and Thr residues in the N terminal of core histone can be phosphorylated, to reduce the interaction of histone and DNA molecule.
C. The acetylation in the N terminal of core histone can stabilize the interaction of histone and DNA.
D. The N terminal of core histone can interact with histone octamer of the neighboring nucleosome, to stabilize 30nm fiber of chromosome.
Which one is correct to say that the 3 'terminal poly-A sequence of mRNA synthesized in the nucleus?()
A. It can be added after any noncoding sequence at the 3 'end of pre-mRNA
B. The same phenomenon can be found in rRNA and tRNA
C. The transcriptional poly-T sequence of template chain
D. Transcription from RNA polymerase II
E. Added after pre-mRNA 3 'end shearing
What about inserting a base into the coding region of a gene?()
A. No impact
B. It will change all amino acid sequences of the protein downstream of the insertion point
C. Depending on the insertion point, it may have different effects on the protein
D. An amino acid will be inserted into the protein sequence
E. Three amino acids will be inserted into the protein sequence
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