What is the transcriptional elongation factor of eukaryotic cells:()
A. TFIID
B. TFIIH
C. GRE
D. TFIIS
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Which is NOT correct about the transcription process of eukaryotic cells:()
A. RNA polymerase can synthesis RNA only when DNA exists.
B. NTPs are the substrates.
C. The direction of RNA chain is 3' -> 5'.
D. The bases of nascent RNA form complementary base-pairing with bases of DNA molecule.
The transcriptional regulation of tryptophan operon is closely related to:()
A. repressor protein
B. transcriptional factor
C. cAMP-CAP
D. Ribosome
Which of the following is NOT correct regarding tryptophan operon:()
A. Ribosome are involved in transcription termination
B. Attenuator is a key regulatory element
C. When Trp is deficient, transcription termination will be initiated in advance
D. Coupled transcription and translation is the molecular basis of transcription regulation
Which of the following descriptions regarding tryptophan operon in E.coli is correct:()
A. it contains regulations in both transcription level and translation level
B. It contains regulations in both initiation step of transcription as well as termination step of transcription.
C. It contains both positive regulation and negative regulation.
D. It contains regulations for enzyme induction as well as enzyme repression.
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