WorksheetsInducible Operon
Total questions: 15
Worksheet time: 15mins
The lac operon is an example of an inducible operon. Which of the following describes the process that occurs when lactose is present?
The lactose binds to the repressor which inactivates it and the repressor binds to the operator to turn translation on.
The lactose binds to the repressor which activates it and the repressor releases from the operator to turn translation on.
The lactose binds to the repressor which inactivates it and the repressor releases from the operator to turn translation on.
The lactose binds to the repressor which activates it and the repressor binds to the operator to turn translation on.
In the lac operon the inducer is
allolactose
glucose
galactose
all of the above
What is 1 in the diagram?
RNA polymerase
Inducer
Repressor
Operator
What is 4 in the diagram?
RNA polymerase
Inducer
Repressor
Operator
What is the role of operons in prokaryote gene expression?
It makes the genes prokaryotes be turned on
It accounts for the regulation of gene activity in response to the needs of the cells
To make DNA for the gene
To make the gene turn of and off
Match the following genetic regions to their roles:
Makes a repressor protein
Regulatory gene
Place where transcription begins
Promotor
The on/off switch where the repressor protein binds
Operator
Codes for the main protein / enzymes
Genes of Operon
A protein that binds to the operator and blocks the RNA polymerase
regulator
repressor
activator
corepressor
The lac operon is referred to as a(n) __________ operon.
inducible
repressible
audible
inaudible
Which of the following best describes an inducible operon?
A) An operon that is always active unless a repressor is present.
B) An operon that is usually off but can be turned on by an inducer.
C) An operon that is always inactive unless an activator is present.
D) An operon that is always on regardless of environmental conditions.
In the context of the lac operon, what role does allolactose play?
A) It acts as a repressor.
B) It acts as an inducer.
C) It acts as a corepressor.
D) It acts as an activator.
What happens to the lac operon when glucose levels are high and lactose is absent?
A) The operon is activated and transcription occurs.
B) The operon is repressed and transcription is inhibited.
C) The operon is partially activated.
D) The operon is unaffected by glucose levels.
Which of the following is a characteristic of an inducible operon?
A) It is typically involved in anabolic pathways.
B) It is typically involved in catabolic pathways.
C) It is not regulated by environmental conditions.
D) It is always active in the presence of a repressor.
In an experiment, a scientist adds an inducer to a bacterial culture. What is the expected outcome if the operon is inducible?
A) The operon will be repressed and gene expression will decrease.
B) The operon will be activated and gene expression will increase.
C) The operon will remain inactive regardless of the inducer.
D) The operon will be permanently turned off.
Which of the following statements about the lac operon is true?
A) The lac operon is a repressible operon.
B) The lac operon is regulated by the presence of tryptophan.
C) The lac operon is an example of an inducible operon.
D) The lac operon is always active in the presence of glucose.
How does the presence of lactose affect the lac operon?
A) Lactose binds to the operator, blocking transcription.
B) Lactose binds to the repressor, inactivating it and allowing transcription.
C) Lactose acts as a corepressor, enhancing repression.
D) Lactose has no effect on the lac operon.
