MEDIUM
Earn 100

Read the following statements about Lac operon:

i. Each operon has its specific operator and specific repressor.

ii. The Y-gene codes for permease, which increases the permeability of the cell to beta-galactosides.

iii. Regulation of lac operon can be visualised as regulation of enzyme synthesis by its substrate.

Select the correct option.

100% studentsanswered this correctly

Important Questions on Molecular Basis of Inheritance

MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
Select the correct match:
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
All of the following are part of an operon except
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression

In biological systems, proteins (repressors and activators) control gene expression. Repressors bind to promoters and inhibit gene expression. Some promoters require activators for gene expression. These constitute a genetic circuit and are analogous to logic gates in digital electronics. A schematic diagram of a genetic circuit in a cell is shown below. Binding of IPTG to LacI activates transcription from Plac. Binding of arabinose (Ara) to AraC activates transcription from Para.

Question Image

Question Image

 The correct statement(s) regarding the given genetic circuit is/are

EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
Which of the following is required as inducer(s) for the expression of Lac operon?
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
Expression of gene regulation results in:
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
The equivalent of a structural gene is:
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
Which of the following enzymes is not produced by E.coli during lactose catabolism?
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
Beadle and Tatum used the organism ______ in their experiment with mutagenic agent, giving One gene-One enzyme hypothesis.
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
When does the lac-operon in E. coli become "switched on"?
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
In operon the segments of DNA which carry codes for the synthesis of proteins are known as
HARD
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
Gene regulation governing lactose operon of E. coli that involves the lac I gene product is:
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
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>Regulation of Gene Expression
In the presence of glucose and lactose, Escherichia coli utilizes glucose. However, lactose also enters the cells because?
EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
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>Regulation of Gene Expression
Which one of these substances will repress the lac operon?
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
Which of the following is required as an inducer for the expression of lac operon?
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
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>Regulation of Gene Expression

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

EASY
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
Identify the correct arrangement of different genes in Lac operon from the following.
MEDIUM
Biology>Genetics and Evolution>Molecular Basis of Inheritance>Regulation of Gene Expression
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.