MEDIUM
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The lac operator is present only in the lac operon; it interacts specifically with ___.

A. Lac repressor

B. Lactose

C. Promoter

D. Co–repressor inducer complex

Choose the correct option from below to fill in the blank.

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Important Questions on Molecular Basis of Inheritance

EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Beadle and Tatum used the organism ______ in their experiment with mutagenic agent, giving One gene-One enzyme hypothesis.
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
When Escherichia coli cells are cultured in a medium where Lactose is absent, the 'i' gene of Lac Operon continues to produce repressor mRNA, because it is
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
When does the lac-operon in E. coli become "switched on"?
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept

Given the diagram of the lac operon showing an operon of inducible enzymes. Identify components and enzymes (A,B,C,D and E) ?

Question Image

HARD
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Gene regulation governing lactose operon of E. coli that involves the lac I gene product is:
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Identify the incorrect phenomenon expressed by a bacterium grown in a medium lacking lactose.
I) Initiates beta-galactosidase activity
II) Bacteria does not produce galactose and glucose
III) Promotor site of transcription unit acts as a repressor
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Identify the correct arrangement of different genes in Lac operon from the following.
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Draw the schematic/diagrammatic presentation of lac operon.
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
The schematic below describes the states of the lac operon in the absence of lactose. Which ONE of the following happens when lactose is present in the cell?
Question Image
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Which one of these substances will repress the lac operon?
HARD
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
What is gene expression? Write two methods of regulation of gene expression in bacteria.
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
The equivalent of a structural gene is:
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
What is lac operon? Describe the structure of controller genes and structural genes with diagrams.
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
In operon the segments of DNA which carry codes for the synthesis of proteins are known as
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Which of the following is required as an inducer for the expression of lac operon?
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Explain the regulation of Lac operon in absence and presence of Lactose as an Inducer.
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Name the inducer which regulates the switching on and off of the lac operon.
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Match the following genes of the Lac operon with their respective products:
  Column-I     Column-II
a  i gene  i ß-galactosidase
b z gene ii Permease
c a gene iii Repressor
d  y gene iv  Transacetylase

Select the correct option.
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
Which of the following is required as inducer(s) for the expression of Lac operon?
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Operon Concept
In the presence of glucose and lactose, Escherichia coli utilizes glucose. However, lactose also enters the cells because?