lac operon

A protein that binds to the operator and blocks the RNA polymerase

• regulator
• repressor
• activator
• corepressor

What is 1 in the diagram?

• RNA polymerase

• Inducer

• Repressor

• Operator

Which of the following is not a structural gene?

• lacZ

• lacY

• lacA

• lacI

Functioning unit of DNA containing a cluster of genes under the control of a single regulatory signal or promoter is termed as

• Operon

• Operator

• Lac

• Repressor protein

Which of the following conditions leads to maximal expression of the lac operon?

• lactose present, glucose absent

• lactose present, glucose present

• lactose absent, glucose absent

• lactose absent, glucose present

lac operon can be found in

• E. coli

• lactose

• human colon

• glucose

The structural gene that codes for protein that increase the permeability of the plasma membrane towards lactose is.

• lacI

• lacZ

• lacY

• lacA

Which sentence is TRUE about structural genes in the absence of lactose?

• Transcription occurred to synthesis enzyme

• Translation occurred to synthesis mRNA

• Transcription occurred to synthesis mRNA

• No transcription and translation occurred

If a promoter was being deleted in lac operon, what would be the effect towards lac operon in the absence of lactose?

• RNA polymerase can transcribe the structural genes

• Enzymes are being produced

• Repressor protein will change its shape

• RNA polymerase cannot bind to lac operon

Which molecules are required to increase rate of transcription when the operon is switched on?

• cAMP and glucose

• CRP and Glucose

• CRP and cAMP

• Lactoce and cAMP