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lac operon

Total questions: 10

Worksheet time: 5mins

Name
Class
Date
1.
A protein that binds to the operator and blocks the RNA polymerase
a)
regulator
b)
repressor
c)
activator
d)
corepressor
2.

In the lac operon the inducer is

a)

allolactose

b)

glucose

c)

galactose

d)

all of the above

3.

What is 1 in the diagram?

a)

RNA polymerase

b)

Inducer

c)

Repressor

d)

Operator

4.

Which of the following is not a structural gene?

a)

lacZ

b)

lacY

c)

lacA

d)

lacI

5.

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

a)

Operon

b)

Operator

c)

Lac

d)

Repressor protein

6.

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

a)

lactose present, glucose absent

b)

lactose present, glucose present

c)

lactose absent, glucose absent

d)

lactose absent, glucose present

7.

lac operon can be found in

a)

E. coli

b)

lactose

c)

human colon

d)

glucose

8.

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

a)

lacI

b)

lacZ

c)

lacY

d)

lacA

9.

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

a)

Transcription occurred to synthesis enzyme

b)

Translation occurred to synthesis mRNA

c)

Transcription occurred to synthesis mRNA

d)

No transcription and translation occurred

10.

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

a)

RNA polymerase can transcribe the structural genes

b)

Enzymes are being produced

c)

Repressor protein will change its shape

d)

RNA polymerase cannot bind to lac operon