The minimum effective size of an operator for lac repressor binding is (A) 5 base pairs (B) 10 base pairs (C) 15 base pairs (D) 17 base pairs

The minimum effective size of an operator for lac repressor binding is (A) 5 base pairs (B) 10 base pairs (C) 15 base pairs (D) 17 base pairs
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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

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

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

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

When does the lac repressor protein bind to the operator? -Biology

Description : When does the lac repressor protein bind to the operator? -Biology

Last Answer : answer:

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)

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

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

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

Repressor binds to DNA sequence and regulate the transcription. This sequence is called (A) Attenuator (B) Terminator (C) Anti terminator (D) Operator

Description : Repressor binds to DNA sequence and regulate the transcription. This sequence is called (A) Attenuator (B) Terminator (C) Anti terminator (D) Operator

Last Answer : Answer : D

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

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

Difference between lac repressor and trp repressor. -Biology

Description : Difference between lac repressor and trp repressor. -Biology

Last Answer : answer:

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

.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.

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)

.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

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.

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)

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

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

Lac operon of E. coli contains _______ is continuity. (A) Regulator and operator genes only (B) Operator and structural genes only (C) Regular and structural genes only (D) Regulator, operator and structural genes

Description : Lac operon of E. coli contains _______ is continuity. (A) Regulator and operator genes only (B) Operator and structural genes only (C) Regular and structural genes only (D) Regulator, operator and structural genes

Last Answer : Answer : D

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

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

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

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

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

Description : 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

Last Answer : Answer : C

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.

In E. coli, during lactose metabolism repressor binds to (a) regulator gene (b) operator gene (c) structural gene (d) promoter gen

Description : In E. coli, during lactose metabolism repressor binds to (a) regulator gene (b) operator gene (c) structural gene (d) promoter gen

Last Answer : (b) operator 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 : (d) Operon - Structural genes, operator and promoter

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

What is the Minimum and maximum deposit in Senior citizen saving scheme a) 500 & 5 Lac b) 1000 & 10 Lacc) 1500 & 15 Lac d) 1000 & 15 Lac

Description : What is the Minimum and maximum deposit in Senior citizen saving scheme a) 500 & 5 Lac b) 1000 & 10 Lac c) 1500 & 15 Lac d) 1000 & 15 Lac

Last Answer : d) 1000 & 15 Lac

Zinc finger motif is formed in some proteins by binding of zinc to (A) Two cysteine residues (B) Two histidine residues (C) Two arginine residues (D) Two cysteine and two histidine residues or two pairs of two cysteine residues each

Description : Zinc finger motif is formed in some proteins by binding of zinc to (A) Two cysteine residues (B) Two histidine residues (C) Two arginine residues (D) Two cysteine and two histidine residues or two pairs of two cysteine residues each

Last Answer : Answer : D

In tRNA molecule, the anticodon arm possesses (A) 5 Base pairs (B) 7 Base pairs (C) 8 Base pairs (D) 10 Base pairs

Description : In tRNA molecule, the anticodon arm possesses (A) 5 Base pairs (B) 7 Base pairs (C) 8 Base pairs (D) 10 Base pairs

Last Answer : Answer : A

The acceptor arm in the tRNA molecule has (A) 5 Base pairs (B) 7 Base pairs (C) 10 Base pairs (D) 20 Base pairs

Description : The acceptor arm in the tRNA molecule has (A) 5 Base pairs (B) 7 Base pairs (C) 10 Base pairs (D) 20 Base pairs

Last Answer : Answer : B

Four members of a band are walking to a night concert. They decide to take a shortcut, but must cross a bridge. Luckily they have one flashlight. Because of the varying size of their instruments, it takes each member a different amount of time to cross the bridge - it takes the first person one minute, the second person two minutes, the third person five minutes and the fourth person ten minutes. They must cross the bridge in pairs, travelling at the slower speed so if the one minute person went with the ten minute person, it would take a total of ten minutes. Since there is only one flashlight, one person must come back across the bridge, then another pair can cross. They only have 17 minutes to cross the bridge and still get to the concert on time. What order should they cross to get eve

Description : Four members of a band are walking to a night concert. They decide to take a shortcut, but must cross a bridge. Luckily they have one flashlight. Because of the varying size of their instruments, it ... bridge and still get to the concert on time. What order should they cross to get eve -Riddles

Last Answer : First, the one minute person and the two minute person must cross the bridge, for a total of two minutes. Then the one minute person should come back with flashlight - total of three ... minutes) and gets the one minute person and they cross together bringing the total to seventeen minutes.

Which one of the following binds to specific nucleotide sequences that are upstream and most distant from the start site? (A) RNA polymerase (B) Repressor (C) Inducer (D) Restriction

Description : Which one of the following binds to specific nucleotide sequences that are upstream and most distant from the start site? (A) RNA polymerase (B) Repressor (C) Inducer (D) Restriction

Last Answer : Answer : A

Which one of the following binds to specific nucleotide sequences? (A) RNA polymerase (B) Repressor (C) Inducer (D) Restriction

Description : Which one of the following binds to specific nucleotide sequences? (A) RNA polymerase (B) Repressor (C) Inducer (D) Restriction

Last Answer : Answer : A

Silencer elements (A) Are trans-acting factors (B) Are present between promoters and the structural genes (C) Decrease the expression of some structural genes (D) Encode specific repressor proteins

Description : Silencer elements (A) Are trans-acting factors (B) Are present between promoters and the structural genes (C) Decrease the expression of some structural genes (D) Encode specific repressor proteins

Last Answer : Answer : C

Positive control of induction is best described as a control system in which an operon functions (A) Unless it is switched off by a derepressed repressor protein (B) Only after a repressor protein is inactivated by an inducer (C) Only after an inducer protein, which can be inactivated by a corepressor, switches it on (D) Only after an inducer protein, which is activated by an inducer, switch it on

Description : Positive control of induction is best described as a control system in which an operon functions (A) Unless it is switched off by a derepressed repressor protein (B) Only after a repressor protein is ... on (D) Only after an inducer protein, which is activated by an inducer, switch it on

Last Answer : Answer : D

The smallest unit of DNA capable of coding for the synthesis of a polypeptide is (A) Operon (B) Repressor gene (C) Cistron (D) Replicon

Description : The smallest unit of DNA capable of coding for the synthesis of a polypeptide is (A) Operon (B) Repressor gene (C) Cistron (D) Replicon

Last Answer : Answer : C

Which of the following pairs is not correctly matched? (A) Uranium - 233 : Fertile material (B) Binding energy : Mass defect (C) Scattering: Absorption cross-section (D) Number of nucleons : Mass number

Description : Which of the following pairs is not correctly matched? (A) Uranium - 233 : Fertile material (B) Binding energy : Mass defect (C) Scattering: Absorption cross-section (D) Number of nucleons : Mass number

Last Answer : (A) Uranium - 233 : Fertile material

What is the size of the longest pencil that can fit in a box with dimensions 12 cm× 10 cm× 8cm? a) 15 b) 15.5 c) 17 d) 17.5 e) 18

Description : What is the size of the longest pencil that can fit in a box with dimensions 12 cm× 10 cm× 8cm? a) 15 b) 15.5 c) 17 d) 17.5 e) 18

Last Answer : Answer: d)

Ten base pairs are present in one turn of the helix in (A) A-DNA (B) B-DNA (C) C-DNA (D) Z-DNA

Description : Ten base pairs are present in one turn of the helix in (A) A-DNA (B) B-DNA (C) C-DNA (D) Z-DNA

Last Answer : Answer : B

Transfer RNAs are classified on the basis of the number of base pairs in (A) Acceptor arm (B) Anticodon arm (C) D arm (D) Extra arm

Description : Transfer RNAs are classified on the basis of the number of base pairs in (A) Acceptor arm (B) Anticodon arm (C) D arm (D) Extra arm

Last Answer : Answer : D

Minimum thickness of the base of a flexible pavement, is (A) 10 cm (B) 15 cm (C) 20 cm (D) 25 cm

Description : Minimum thickness of the base of a flexible pavement, is (A) 10 cm (B) 15 cm (C) 20 cm (D) 25 cm

Last Answer : Answer: Option A

A simply supported beam 6 m long and of effective depth 50 cm, carries a uniformly distributed load 2400 kg/m including its self weight. If the lever arm factor is 0.85 and permissible tensile stress of steel is 1400 kg/cm2 , the area of steel required, is (A) 14 cm(B) 15 cm2(C) 16 cm2(D) 17 cm

Description : A simply supported beam 6 m long and of effective depth 50 cm, carries a uniformly distributed load 2400 kg/m including its self weight. If the lever arm factor is 0.85 and permissible tensile stress of steel is 1400 kg/cm2 ... area of steel required, is (A) 14 cm (B) 15 cm2 (C) 16 cm2 (D) 17 cm

Last Answer : Answer: Option C

If the effective working time is 7 hours and per batch time of concrete is 3 minutes, the output of a concrete mixer of 150 litre capacity, is (A) 15,900 litres (B) 16,900 litres (C) 17,900 litres (D) 18,900 litres

Description : If the effective working time is 7 hours and per batch time of concrete is 3 minutes, the output of a concrete mixer of 150 litre capacity, is (A) 15,900 litres (B) 16,900 litres (C) 17,900 litres (D) 18,900 litres

Last Answer : (D) 18,900 litres

f the temperature falls below 18 degrees, the heating is switched on. When the temperature reaches 21 degrees, the heating is switched off. What is the minimum set of test input values to cover all valid equivalence partitions? A. 15, 19 and 25 degrees B. 17, 18, 20 and 21 degrees C. 18, 20 and 22 degrees D. 16 and 26 degrees

Description : f the temperature falls below 18 degrees, the heating is switched on. When the temperature reaches 21 degrees, the heating is switched off. What is the minimum set of test input values to cover all valid equivalence ... 17, 18, 20 and 21 degrees C. 18, 20 and 22 degrees D. 16 and 26 degrees

Last Answer : A. 15, 19 and 25 degrees

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