What is the role of inducers in the positive regulatory system?()
A. It's called "co-inhibitor"
B. Prevent binding DNA of repressor protein
C. DNA that helps activate protein binding
D. Instead of protein, it binds directly to the DNA
E. Impossible, inducers are only used for negative regulatory mechanisms
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Why do bacteria have multiple σ factors?()
A. Some play a role in the transcription process, others in the translation process
B. Enabling cells to simultaneously transcribe multiple genes that respond to different environments
C. The transcription of each gene requires the participation of different σ factors
D. A σ factor is combined on the leading chain and the other on the following chain.
E. Some σ factors activate gene transcription, others inhibit expression
DNA polymerase is not needed in DNA replication.()
A. Primer
B. Template chain that can be read by 3'-5'
C. Promoter
D. dNTPs
E. 3'-OH free end
SD sequence plays the same role in translation as () in transcription.
A. Promoter
B. σ factor
C. RNA polymerase
D. Terminator
E. Initiator codon
The function of DNA gyrase in DNA replication is()?
A. primer for synthesis of the replication initiation
B. catalyze transport reaction
C. the DNA double strand unwinding before the replication fork
D. the DNA on the replication fork is broken by breaking the hydrogen bond
E. enables replication to move in both directions from the start
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