Binding of RNA polymerase holoenzyme to the promoter region of lac operon is facilitated by (A) Catabolite gene activator protein (CAP) (B) cAMP (C) CAP-cAMP complex (D) None of these

Binding of RNA polymerase holoenzyme to the promoter region of lac operon is facilitated by (A) Catabolite gene activator protein (CAP) (B) cAMP (C) CAP-cAMP complex (D) None of these
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Lactose or its analogues act as positive regulators of lac operon by (A) Attaching to i gene and preventing its expression (B) Increasing the synthesis of catabolite gene activator protein (C) Attaching to promoter region and facilitating the binding of RNA polymerase holoenzyme (D) Binding to repressor subunits so that the repressor cannot attach to the operator locus

Description : Lactose or its analogues act as positive regulators of lac operon by (A) Attaching to i gene and preventing its expression (B) Increasing the synthesis of catabolite gene activator protein (C) ... holoenzyme (D) Binding to repressor subunits so that the repressor cannot attach to the operator locus

Last Answer : Answer : D

RNA polymerase holoenzyme binds to lac operon at the following site: (A) i gene (B) z gene (C) Operator locus (D) Promoter region

Description : RNA polymerase holoenzyme binds to lac operon at the following site: (A) i gene (B) z gene (C) Operator locus (D) Promoter region

Last Answer : Answer : D

The enzymes encoded by z, y and a genes of lac operon are inducible, and their inducer is (A) Lactose (B) Allo-lactose (C) Catabolite gene activator protein (D) All of these

Description : The enzymes encoded by z, y and a genes of lac operon are inducible, and their inducer is (A) Lactose (B) Allo-lactose (C) Catabolite gene activator protein (D) All of these

Last Answer : Answer : B

The catabolite repression is mediated by a catabolite gene activator protein (CAP) in conjunction with (A) AMP (B) GMP (C) cAMP (D) Cgmp

Description : The catabolite repression is mediated by a catabolite gene activator protein (CAP) in conjunction with (A) AMP (B) GMP (C) cAMP (D) Cgmp

Last Answer : Answer : C

Select the incorrect statement out of the five given below about lac operon when Lactose is present in the medium. a) Gene – A gets transcribed into mRNA which produces β-galactoside permease b) Inducer-Repressor complex is formed c) Lactose inactivates repressor protein d) RNA polymerase transcribe Z-gene, Y-gene and A-gene e) Allolactose is the inducer of lac operon

Description : Select the incorrect statement out of the five given below about lac operon when Lactose is present in the medium. a) Gene - A gets transcribed into mRNA which produces β-galactoside permease b) ... polymerase transcribe Z-gene, Y-gene and A-gene e) Allolactose is the inducer of lac operon

Last Answer : Gene – A gets transcribed into mRNA which produces β-galactoside permease b) Inducer-Repressor complex is formed

Transcription of structural genes of lac operon is prevented by binding of the repressor tetramer to (A) i gene (B) Operator locus (C) Promoter (D) z gene

Description : Transcription of structural genes of lac operon is prevented by binding of the repressor tetramer to (A) i gene (B) Operator locus (C) Promoter (D) z gene

Last Answer : Answer : B

The ‘rho’ (ρ) factor is involved (A) To increase the rate of RNA synthesis (B) In binding catabolite repressor to the promoter region (C) In proper termination of transcription (D) To allow proper initiation of transcriptide

Description : The ‘rho’ (ρ) factor is involved (A) To increase the rate of RNA synthesis (B) In binding catabolite repressor to the promoter region (C) In proper termination of transcription (D) To allow proper initiation of transcriptide

Last Answer : Answer : C

Expression of structural genes of lac operon is affected by all the following except (A) Lactose or its analogues (B) Repressor tetramer (C) cAMP (D) CAP-cAMP complex

Description : Expression of structural genes of lac operon is affected by all the following except (A) Lactose or its analogues (B) Repressor tetramer (C) cAMP (D) CAP-cAMP complex

Last Answer : Answer : C

The ribosome binding site A- forms a stem-loop structure in the RNA B- is located upstream of the promoter sequence C- .is located immediately upstream of the start codon D- is more likely to be associated with an operon than with a gene encoding a single protein

Description : The ribosome binding site A- forms a stem-loop structure in the RNA B- is located upstream of the promoter sequence C- .is located immediately upstream of the start codon D- is more likely to be associated with an operon than with a gene encoding a single protein

Last Answer : .is located immediately upstream of the start codon

The rivosome binding site A- forms a sltem- loop structure in the RNA B- is located upstream of the promoter sequence C- is located immediately upstream of the start codon D- is more likely to be associated with an operon than with a gene encoding a single protein

Description : The rivosome binding site A- forms a sltem- loop structure in the RNA B- is located upstream of the promoter sequence C- is located immediately upstream of the start codon D- is more likely to be associated with an operon than with a gene encoding a single protein

Last Answer : is located immediately upstream of the start codon

The ribosome binding site A- forms a stem-loop structure in the RNA B- is located upstream of the promoter sequence C- .is located immediately upstream of the start codon D- is more likely to be associated with an operon than with a gene encoding a single protein

Description : The ribosome binding site A- forms a stem-loop structure in the RNA B- is located upstream of the promoter sequence C- .is located immediately upstream of the start codon D- is more likely to be associated with an operon than with a gene encoding a single protein

Last Answer : .is located immediately upstream of the start codon

The function of a repressor protein in an operon system is to prevent synthesis by binding to (A) The ribosome (B) A specific region of the operon preventing transcription of structural genes (C) The RNA polymerase (D) A specific region of the mRNA preventing translation to protein

Description : The function of a repressor protein in an operon system is to prevent synthesis by binding to (A) The ribosome (B) A specific region of the operon preventing transcription of structural genes (C) The RNA polymerase (D) A specific region of the mRNA preventing translation to protein

Last Answer : Answer : B

The region of the Lac operon which must be free from structural gene transcription to occur is (A) The operator locus (B) The promoter site (C) The ‘a’ gene (D) The ‘i’ gene

Description : The region of the Lac operon which must be free from structural gene transcription to occur is (A) The operator locus (B) The promoter site (C) The ‘a’ gene (D) The ‘i’ gene

Last Answer : Answer : A

The coding sequences in lac operon include (A) i gene (B) i gene, operator locus and promoter (C) z, y and a genes (D) i, z, y and a genes

Description : The coding sequences in lac operon include (A) i gene (B) i gene, operator locus and promoter (C) z, y and a genes (D) i, z, y and a genes

Last Answer : Answer : D

Lac operon is a cluster of (A) Three structural genes (B) Three structural genes and their promoter (C) A regulatory gene, an operator and a promoter (D) A regulatory gene, an operator, a promoter and three structural genes

Description : Lac operon is a cluster of (A) Three structural genes (B) Three structural genes and their promoter (C) A regulatory gene, an operator and a promoter (D) A regulatory gene, an operator, a promoter and three structural genes

Last Answer : Answer : D

All of the following statements about eukaryotic promoters are true except (A) They may be located upstream or down stream from the structural gene (B) They have two consensus sequences (C) One consensus sequence binds RNA polymerase (D) Mutations in promoter region can decrease the efficiency of transcription of the structural gene

Description : All of the following statements about eukaryotic promoters are true except (A) They may be located upstream or down stream from the structural gene (B) They have two consensus sequences ( ... (D) Mutations in promoter region can decrease the efficiency of transcription of the structural gene

Last Answer : Answer : A

In the lac operon concept, a protein molecule is (A) Operator (B) Inducer (C) Promoter (D) Repressor

Description : In the lac operon concept, a protein molecule is (A) Operator (B) Inducer (C) Promoter (D) Repressor

Last Answer : Answer : D

Negative regulation of protein synthesis is accomplished by A- allosteric inhibition B- the binding of RNA polymerase to the promoter C- the binding of a repressor to the DNA D- the binding of a repressor to the RNA polymerase

Description : Negative regulation of protein synthesis is accomplished by A- allosteric inhibition B- the binding of RNA polymerase to the promoter C- the binding of a repressor to the DNA D- the binding of a repressor to the RNA polymerase

Last Answer : the binding of a repressor to the DNA

Lac operon’ in E. coli, is induced by (a) ‘I’ gene (b) promoter gene (c) β-galactosidase (d) lactose.

Description : Lac operon’ in E. coli, is induced by (a) ‘I’ gene (b) promoter gene (c) β-galactosidase (d) lactose.

Last Answer : (c) β-galactosidase

The binding of prokaryotic DNA dependent RNA polymerase to promoter sits of genes is inhibited by the antibiotic: (A) Streptomycin (B) Rifamcin (C) Aueromycin (D) Puromycin

Description : The binding of prokaryotic DNA dependent RNA polymerase to promoter sits of genes is inhibited by the antibiotic: (A) Streptomycin (B) Rifamcin (C) Aueromycin (D) Puromycin

Last Answer : Answer : B

The binding of prokaryotic DNA dependent RNA polymerase to promoter sites of genes is inhibited by the antibiotic: (A) Puromycin (B) Rifamycin (C) Terramycin (D) Streptomycin

Description : The binding of prokaryotic DNA dependent RNA polymerase to promoter sites of genes is inhibited by the antibiotic: (A) Puromycin (B) Rifamycin (C) Terramycin (D) Streptomycin

Last Answer : Answer : B

To commence structural gene transcription the region which should be free on lac operation is (A) Promoter site (B) Operator locus (C) Y gene (D) A gene

Description : To commence structural gene transcription the region which should be free on lac operation is (A) Promoter site (B) Operator locus (C) Y gene (D) A gene

Last Answer : Answer : B

Which of the following genes of the E.coli “Lac operon” codes for a constitutive protein? (A) The ‘a’ gene (B) The ‘i’ gene (C) The ‘c’ gene (D) The ‘z’ gene

Description : Which of the following genes of the E.coli “Lac operon” codes for a constitutive protein? (A) The ‘a’ gene (B) The ‘i’ gene (C) The ‘c’ gene (D) The ‘z’ gene

Last Answer : Answer : B

The regulatory i gene of lac operon (A) Is inhibited by lacotse (B) Is inhibited by its own product, the repressor protein (C) Forms a regulatory protein which increases the expression of downstream structural genes (D) Is constitutively expressed

Description : The regulatory i gene of lac operon (A) Is inhibited by lacotse (B) Is inhibited by its own product, the repressor protein (C) Forms a regulatory protein which increases the expression of downstream structural genes (D) Is constitutively expressed

Last Answer : Answer : D

Select the two correct statements out of the four (i – iv) statements given below about lac operon. (i) Glucose or galactose may bind with the repressor and inactivate it. (ii) In the absence of lactose, the repressor binds with the operator region. (iii)The z-gene codes for permease. (iv) This was elucidated by Francois Jacob and Jacques Monod. The correct statements are (a) (ii) and (iii) (b) (i) and (iii) (c) (ii) and (iv) (d) (i) and (ii)

Description : Select the two correct statements out of the four (i - iv) statements given below about lac operon. (i) Glucose or galactose may bind with the repressor and inactivate it. (ii) In the absence of lactose, the repressor binds with the ... (iii) (b) (i) and (iii) (c) (ii) and (iv) (d) (i) and (ii)

Last Answer : (c) (ii) and (iv)

Trancription of z, y and a genes of lac operon is prevented by (A) Lactose (B) Allo-lactose (C) Repressor (D) cAMP

Description : Trancription of z, y and a genes of lac operon is prevented by (A) Lactose (B) Allo-lactose (C) Repressor (D) cAMP

Last Answer : Answer : C

.Gene regulation governing lactose operon of E.coli that involves the lac I gene product is (a) negative and repressible because repressor protein prevents transcription (b) feedback inhibition because excess of β-galactosidase can switch off transcription (c) positive and inducible because it can be induced by lactose (d) negative and inducible because repressor protein prevents transcription.

Description : .Gene regulation governing lactose operon of E.coli that involves the lac I gene product is (a) negative and repressible because repressor protein prevents transcription (b) feedback inhibition ... be induced by lactose (d) negative and inducible because repressor protein prevents transcription.

Last Answer : (d) negative and inducible because repressor protein prevents transcription.

Gene regulation governing lactose operon of E.coli that involves the lac I gene product is (a) negative and repressible because repressor protein prevents transcription (b) feedback inhibition because excess of β-galactosidase can switch off transcription (c) positive and inducible because it can be induced by lactose (d) negative and inducible because repressor protein prevents transcription.

Description : Gene regulation governing lactose operon of E.coli that involves the lac I gene product is (a) negative and repressible because repressor protein prevents transcription (b) feedback inhibition ... be induced by lactose (d) negative and inducible because repressor protein prevents transcription.

Last Answer : (d) negative and inducible because repressor protein prevents transcription.

Ribonucleotides of RNA primer are replaced by deoxyribonucleotides by the enzyme: (A) DNA polymerase I (B) DNA polymerase II (C) DNA polymerase III holoenzyme (D) All of these

Description : Ribonucleotides of RNA primer are replaced by deoxyribonucleotides by the enzyme: (A) DNA polymerase I (B) DNA polymerase II (C) DNA polymerase III holoenzyme (D) All of these

Last Answer : Answer : A

Deoxyribonucleotides are added to RNA primer by (A) DNA polymerase I (B) DNA polymerase II (C) DNA polymerase III holoenzyme (D) All of these

Description : Deoxyribonucleotides are added to RNA primer by (A) DNA polymerase I (B) DNA polymerase II (C) DNA polymerase III holoenzyme (D) All of these

Last Answer : Answer : C

The region of DNA known as TATA BOX is the site for binding of (A) DNA polymerase (B) DNA topoisomerase (C) DNA dependent RNA polymerase (D) Polynucleotide phosphorylase

Description : The region of DNA known as TATA BOX is the site for binding of (A) DNA polymerase (B) DNA topoisomerase (C) DNA dependent RNA polymerase (D) Polynucleotide phosphorylase

Last Answer : Answer : C

In the process of transcription in bacterial cells (A) Initiation requires rho protein (B) RNA polymerase incorporates methylated bases in correct sequence (C) Both the sigma unit and core enzymes of RNA polymerase are required for accurate promotor site binding (D) Primase is necessary for initiation

Description : In the process of transcription in bacterial cells (A) Initiation requires rho protein (B) RNA polymerase incorporates methylated bases in correct sequence (C) Both the sigma unit and core ... RNA polymerase are required for accurate promotor site binding (D) Primase is necessary for initiation

Last Answer : Answer : C

The gene of lac operon which has constitutive expression is (A) i (B) c (C) z (D) p

Description : The gene of lac operon which has constitutive expression is (A) i (B) c (C) z (D) p

Last Answer : Answer : A

.In negative operon, (a) co-repressor binds with repressor (b) co-repressor does not bind with repressor (c) co-repressor binds with inducer (d) cAMP have negative effect on lac operon. (

Description : .In negative operon, (a) co-repressor binds with repressor (b) co-repressor does not bind with repressor (c) co-repressor binds with inducer (d) cAMP have negative effect on lac operon. (

Last Answer : co-repressor binds with repressor

In pKO1 plasmid, galactose kinase gene is a reporter gene which lacks ___________ gene. a. Initiation codon b. Promoter c. Activator d. Termination

Description : In pKO1 plasmid, galactose kinase gene is a reporter gene which lacks ___________ gene. a. Initiation codon b. Promoter c. Activator d. Termination

Last Answer : b. Promoter

During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called? (a) AAAT box (b) TATA box (c) GGTT box (d) CAAT box

Description : During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called? (a) AAAT box (b) TATA box (c) GGTT box (d) CAAT box

Last Answer : (c) GGTT box

During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called? (a) AAAT box (b) TATA box (c) GGTT box (d) CAAT box

Description : During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called? (a) AAAT box (b) TATA box (c) GGTT box (d) CAAT box

Last Answer : (b) TATA box

The transcription initiation factor associated with the RNA polymerase holoenzyme in prokaryotes is (a) β (b) ω (c) σ (d) αI

Description : The transcription initiation factor associated with the RNA polymerase holoenzyme in prokaryotes is (a) β (b) ω (c) σ (d) αI

Last Answer : c) σ (

In the ’lac operon’ concept, which of the following is a protein? (A) Operator (B) Repressor (C) Inducer (D) Vector

Description : In the ’lac operon’ concept, which of the following is a protein? (A) Operator (B) Repressor (C) Inducer (D) Vector

Last Answer : Answer : B

Match the following genes of the Lac operon with their respective products. (A) i gene (i) b-galactosidase (B) z gene (ii) Permease (C) a gene (iii)Repressor (D) y gene (iv) Transacetylase Select the correct option. (A) (B) (C) (D) (a) (iii) (iv) (i) (ii) (b) (i) (iii) (ii) (iv) (c) (iii) (i) (ii) (iv) (d) (iii) (i) (iv) (ii)

Description : Match the following genes of the Lac operon with their respective products. (A) i gene (i) b-galactosidase (B) z gene (ii) Permease (C) a gene (iii)Repressor (D) y gene (iv) Transacetylase Select the correct option. (A) (B) (C) ( ... ) (iii) (ii) (iv) (c) (iii) (i) (ii) (iv) (d) (iii) (i) (iv) (ii)

Last Answer : (a) (iii) (iv) (i) (ii)

.E.coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because (a) the lac operon is constitutively active in these cells (b) they cannot synthesise functional beta galactosidase (c) in the presence of glucose, E.coli cells do not utilise lactose (d) they cannot transport lactose from the medium into the cell.

Description : .E.coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because (a) the lac operon is constitutively active in these cells ( ... coli cells do not utilise lactose (d) they cannot transport lactose from the medium into the cell.

Last Answer : (b) they cannot synthesise functional beta galactosidase

.The lac operon consists of (a) four regulatory genes only (b) one regulatory gene and three structural genes (c) two regulatory genes and two structural genes (d) three regulatory genes and three structural genes.

Description : .The lac operon consists of (a) four regulatory genes only (b) one regulatory gene and three structural genes (c) two regulatory genes and two structural genes (d) three regulatory genes and three structural genes.

Last Answer : (b) one regulatory gene and three structural genes

Match the following genes of the Lac operon with their respective products. (A) i gene (i) b-galactosidase (B) z gene (ii) Permease (C) a gene (iii)Repressor (D) y gene (iv) Transacetylase Select the correct option. (A) (B) (C) (D) (a) (iii) (iv) (i) (ii) (b) (i) (iii) (ii) (iv) (c) (iii) (i) (ii) (iv) (d) (iii) (i) (iv) (ii)

Description : Match the following genes of the Lac operon with their respective products. (A) i gene (i) b-galactosidase (B) z gene (ii) Permease (C) a gene (iii)Repressor (D) y gene (iv) Transacetylase Select the correct option. (A) (B) (C) ( ... ) (iii) (ii) (iv) (c) (iii) (i) (ii) (iv) (d) (iii) (i) (iv) (ii)

Last Answer : d) (iii) (i) (iv) (ii)

Which one of the following is NOT part of an operon? a. Regulatory gene b. Operator c. Promoter d. Structural genes

Description : Which one of the following is NOT part of an operon? a. Regulatory gene b. Operator c. Promoter d. Structural genes

Last Answer : d. Structural genes

8. Non coding sequences present within a gene is called: (a) Exon (b) Operon (c) Promoter (d) Intron

Description : 8. Non coding sequences present within a gene is called: (a) Exon (b) Operon (c) Promoter (d) Intron

Last Answer : (d) Intron

An important step in protein synthesis is transcription. Which of the following statement(s) is/are true concerning this process? a. The first step in gene transcription involves separating the double helix of DNA by an enzyme known as DNA polymerase b. The initial product of DNA transcription is called heterogeneous nuclear RNA which codes directly for proteins c. After processing is complete, the mRNA is exported from the nucleus to the cytoplasm d. Only one protein can be produced from an initial mRNA strand

Description : An important step in protein synthesis is transcription. Which of the following statement(s) is/are true concerning this process? a. The first step in gene transcription involves separating the double helix ... nucleus to the cytoplasm d. Only one protein can be produced from an initial mRNA strand

Last Answer : Answer: c Transcription of a gene begins at an initiation site associated with a specific DNA sequence, termed a promoter region. After binding to DNA, the RNA polymerase opens up a short ... different proteins from the same gene. mRNA is exported from the nucleus only after processing is complete

During transcription, the DNA site at which RNA polymerase binds is called (a) promoter (b) regulator (c) receptor (d) enhancer.

Description : During transcription, the DNA site at which RNA polymerase binds is called (a) promoter (b) regulator (c) receptor (d) enhancer.

Last Answer : d) enhancer

During transcription, the DNA site at which RNA polymerase binds is called (a) promoter (b) regulator (c) receptor (d) enhancer.

Description : During transcription, the DNA site at which RNA polymerase binds is called (a) promoter (b) regulator (c) receptor (d) enhancer.

Last Answer : (a) promoter

In Lac-operon, repressor protein binds to

Description : In Lac-operon, repressor protein binds to

Last Answer : In Lac-operon, repressor protein binds to A. Regulator gene B. Operator gene C. Promoter gene D. Structural gene

Which one of the following is wrongly matched? (a) Transcription - Writing information from DNA to tRNA. (b) Translation - Using information in mRNA to make protein. (c) Repressor protein - Binds to operator to stop enzyme synthesis. (d) Operon - Structural genes, operator and promoter.

Description : Which one of the following is wrongly matched? (a) Transcription - Writing information from DNA to tRNA. (b) Translation - Using information in mRNA to make protein. (c) Repressor protein - Binds to operator to stop enzyme synthesis. (d) Operon - Structural genes, operator and promoter.

Last Answer : (c) Repressor protein - Binds to operator to stop enzyme synthesis.