A: where the
repressor binds to regulate gene expression in an operon.
B: controlled
by promoter.
C: is induced
by lactose.
D: is repressed
by tryptophan.
举一反三
- Operator: ( ) A: An operator is a DNA region that is working with promoter for genes to express. B: An operator is a DNA region at 5’ of a gene for a repressor to bind to prevent gene expression. C: An operator is a repressor protein to help genes to express. D: An operator is a repressor protein to inhibit genes to express.
- Operon do not include( ): A: promoter B: regulatory sequence C: operator D: structural gene E: trans-acting factor
- When only glucose is available to E. coli in the culture medium: ( ) A: cAMP-CAP is bound to the promoter； B: cAMP-CAP is not bound to the promoter； C: The repressor is not bound to the operator； D: The lac operon is turn on
- The operator is A: Another name for the terminator of a gene B: A DNA site bound by repressor proteins C: A protein that coordinates gene expression D: A part in the leader region of mRNA
- Operator is bound by A: activator B: repressor C: promoter D: enhancer E: silencer
内容
- 0
If the magnetic field B through<br/>a loop of wire is increasing, the<br/>induced magnetic field will be A: in<br/>the same direction as B B: in<br/>the opposite direction as B C: perpendicular<br/>to B D: at<br/>an acute angle to B E: there<br/>is no induced magnetic field
- 1
Control of gene expression<br/>by preventing a gene from being expressed. () A: Transcription B: Induction C: Translation D: Replication E: Repression
- 2
The<br/>anti-UV mutation of microorganisms must be induced by ultraviolet<br/>rays.(<br/>)
- 3
(<br/>) can be determined by the left hand rule. A: The induced force on the moving charged particles in the magnetic<br/>field. B: The direction of the induced force on the moving charged particles in<br/>the magnetic field. C: The induced electromagneto motive force on the moving conductor in<br/>the magnetic field. D: The direction of the induced electro-motive force on the moving<br/>conductor in the magnetic field.
- 4
Which<br/>of following can cause the great variation of influenza virus and<br/>wide epidemic:() A: gene<br/>reassortment B: gene<br/>recombination C: transduction D: transformation E: conjunction