Which enzyme will be produced in a cell if there is a nonsense mutation in the lac Y gene? (a) Transacetylase (b) Lactose permease and transacetylase (c) β-galactosidase (d) Lactose permease

Which enzyme will be produced in a cell if there is a
nonsense mutation in the lac Y gene?
(a) Transacetylase
(b) Lactose permease and transacetylase
(c) β-galactosidase
(d) Lactose permease
by

1 Answer

Answer :

β-galactosidase
by

Related questions

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)

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

.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.

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

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.

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)

.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 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 enzyme deficient in Sandhoff’s disease is (A) α-Fucosidase (B) Hexosaminidase A and B (C) β-Galactosidase (D) β-Glucosidase

Description : The enzyme deficient in Sandhoff’s disease is (A) α-Fucosidase (B) Hexosaminidase A and B (C) β-Galactosidase (D) β-Glucosidase

Last Answer : Answer : B

The enzyme deficient in Krabbe’s disease is (A) Hexosaminidase A(B) Arylsuphatase A (C) β-Galactosidase (D) α-Fucosidase

Description : The enzyme deficient in Krabbe’s disease is (A) Hexosaminidase A(B) Arylsuphatase A (C) β-Galactosidase (D) α-Fucosidase

Last Answer : Answer : C

Farber’s disease is due to the deficiency of the enzyme: (A) α-Galactosidase (B) Ceramidase (C) β-Glucocerebrosidase (D) Arylsulphatase A.

Description : Farber’s disease is due to the deficiency of the enzyme: (A) α-Galactosidase (B) Ceramidase (C) β-Glucocerebrosidase (D) Arylsulphatase A.

Last Answer : Answer : B

Krabbe’s disease is due to the deficiency of the enzyme: (A) Ceramide lactosidase (B) Ceramidase (C) β-Galactosidase (D) GM1 β-Galactosidase

Description : Krabbe’s disease is due to the deficiency of the enzyme: (A) Ceramide lactosidase (B) Ceramidase (C) β-Galactosidase (D) GM1 β-Galactosidase

Last Answer : Answer : C

Gaucher’s disease is due to the deficiency of the enzyme: (A) α-Fucosidase (B) β-Galactosidase (C) β-Glucosidase (D) Sphingomyelinase

Description : Gaucher’s disease is due to the deficiency of the enzyme: (A) α-Fucosidase (B) β-Galactosidase (C) β-Glucosidase (D) Sphingomyelinase

Last Answer : Answer : C

The enzyme deficient in Fabry’s disease is (A) α-Galactosidase (B) β-Galactosidase (C) α-Glucosidase (D) β-Glucosidase

Description : The enzyme deficient in Fabry’s disease is (A) α-Galactosidase (B) β-Galactosidase (C) α-Glucosidase (D) β-Glucosidase

Last Answer : Answer : A

Gaucher’s disease is due to deficiency of the enzyme: (A) Sphingomyelinase (B) Glucocerebrosidase (C) Galactocerbrosidase (D) β-Galactosidase

Description : Gaucher’s disease is due to deficiency of the enzyme: (A) Sphingomyelinase (B) Glucocerebrosidase (C) Galactocerbrosidase (D) β-Galactosidase

Last Answer : Answer : B

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

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

5. Lac operon transcribed when a) lactose is needed by the cell b) lactose is available to the cell c) lactic acid is needed by the cell d) lactic acid is available to the cell

Description : 5. Lac operon transcribed when a) lactose is needed by the cell b) lactose is available to the cell c) lactic acid is needed by the cell d) lactic acid is available to the cell

Last Answer : b) lactose is available to the cell

β -Galactosidase is deficient in (A) Fabry’s disease (B) Krabbe’s disease (C) Gaucher’s disease (D) Metachromatic leukodystrophy

Description : β -Galactosidase is deficient in (A) Fabry’s disease (B) Krabbe’s disease (C) Gaucher’s disease (D) Metachromatic leukodystrophy

Last Answer : Answer : B

If the codon UAC on mRNA changes into UAG as a result of a base substitution in DNA, it will result in (A) Silent mutation (B) Acceptable mis-sense mutation (C) Nonsense mutation (D) Frameshift mutation

Description : If the codon UAC on mRNA changes into UAG as a result of a base substitution in DNA, it will result in (A) Silent mutation (B) Acceptable mis-sense mutation (C) Nonsense mutation (D) Frameshift mutation

Last Answer : Answer : C

A silent mutation is most likely to result from (A) Substitution of the first base of a codon (B) Substitution of the third base of a codon (C) Conversion of a nonsense codon into a sense codon (D) Conversion of a sense codon into a nonsense codon

Description : A silent mutation is most likely to result from (A) Substitution of the first base of a codon (B) Substitution of the third base of a codon (C) Conversion of a nonsense codon into a sense codon (D) Conversion of a sense codon into a nonsense codon

Last Answer : Answer : B

Substitution of a base can result in a (A) Silent mutation (B) Mis-sense mutation (C) Nonsense mutation(D) All of these

Description : Substitution of a base can result in a (A) Silent mutation (B) Mis-sense mutation (C) Nonsense mutation(D) All of these

Last Answer : Answer : D

In the following partial sequence of mRNA, a mutation of the template DNA results in a change in codon 91 to UAA. The type of mutation is 88 89 90 91 92 93 94 GUC GAC CAG UAG GGC UAA CCG (A) Missene (B) Silent (C) Nonsense (D) Frame shit

Description : In the following partial sequence of mRNA, a mutation of the template DNA results in a change in codon 91 to UAA. The type of mutation is 88 89 90 91 92 93 94 GUC GAC CAG UAG GGC UAA CCG (A) Missene (B) Silent (C) Nonsense (D) Frame shit

Last Answer : Answer : B

Cancer cells may become resistant to amethopterin by (A) Developing mechanisms to destroy amethopterin (B) Amplification of dihydrofolate reducatse gene (C) Mutation in the dihydrofolate reductase gene so that the enzyme is no longer inhibited by amethopterin (D) Developing alternate pathway of thymidylate synthesis

Description : Cancer cells may become resistant to amethopterin by (A) Developing mechanisms to destroy amethopterin (B) Amplification of dihydrofolate reducatse gene (C) Mutation in the dihydrofolate reductase ... is no longer inhibited by amethopterin (D) Developing alternate pathway of thymidylate synthesis

Last Answer : Answer : B

A specific BRCA1 cancer-predisposing gene mutation seems to occur more frequently among women of which descent? a) Ashkanazi Jewish Expression of the BRCA1 gene is an example of inheritance in the development of breast cancer. b) Mediterranean Glucose-6-phosphate dehydrogenase deficiency (G6PD) is a common enzyme abnormality that affects millions of people throughout the world, especially those of Mediterranean, South East Asian, African, Middle Eastern, and Near Eastern origin.

Description : A specific BRCA1 cancer-predisposing gene mutation seems to occur more frequently among women of which descent? a) Ashkanazi Jewish Expression of the BRCA1 gene is an example of ... of treatment for tuberculosis) are at significantly increased risk for developing isoniazid-induced hepatitis.

Last Answer : a) Ashkanazi Jewish Expression of the BRCA1 gene is an example of inheritance in the development of breast cancer.

If a gene mutation prevents formation of an enzyme normally used by a lysosomes, a disease may result known as (A) Lysosomal abstracted disease (B) Lysosomal secretory disease (C) Lysosomal storage disease (D) All A, B and C

Description : If a gene mutation prevents formation of an enzyme normally used by a lysosomes, a disease may result known as (A) Lysosomal abstracted disease (B) Lysosomal secretory disease (C) Lysosomal storage disease (D) All A, B and C

Last Answer : (C) Lysosomal storage disease

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

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

In lac operon, lactose acts are

Description : In lac operon, lactose acts are

Last Answer : In lac operon, lactose acts are A. Inducer B. Co-inducer C. Repressor D. Co-repressor

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

Which of the following is required as inducer(s) for the expression of Lac operon? (a) Lactose (b) Lactose and galactose (c) Glucose (d) Galactose

Description : Which of the following is required as inducer(s) for the expression of Lac operon? (a) Lactose (b) Lactose and galactose (c) Glucose (d) Galactose

Last Answer : (c) Glucose

The wild type E.coli cells are growing in normal medium with glucose. They are transferred to a medium containing only lactose as sugar. Which of the following changes take place? (a) The lac operon is induced. (b) E.coli cells stop dividing. (c) The lac operon is repressed. (d) All operons are induced.

Description : The wild type E.coli cells are growing in normal medium with glucose. They are transferred to a medium containing only lactose as sugar. Which of the following changes take place? (a) The lac operon is ... ) E.coli cells stop dividing. (c) The lac operon is repressed. (d) All operons are induced.

Last Answer : (a) The lac operon is induced

What does “lac” refer to in what we call the lac operon? (a) Lactose (b) Lactase (c) Lac insect (d) The number 1,00,000

Description : What does “lac” refer to in what we call the lac operon? (a) Lactose (b) Lactase (c) Lac insect (d) The number 1,00,000

Last Answer : (a) Lactose

Which of the following is required as inducer(s) for the expression of Lac operon? (a) Lactose (b) Lactose and galactose (c) Glucose (d) Galactose

Description : Which of the following is required as inducer(s) for the expression of Lac operon? (a) Lactose (b) Lactose and galactose (c) Glucose (d) Galactose

Last Answer : Lactose

α-Galactosidase enzyme is defective in (A) Tay-sach’s disease (B) Refsum’s disease (C) Sandhoff’s disease (D) Fabry’s disease

Description : α-Galactosidase enzyme is defective in (A) Tay-sach’s disease (B) Refsum’s disease (C) Sandhoff’s disease (D) Fabry’s disease

Last Answer : Answer : D

The colonies of recombinant bacteria appear white in contrast to blue colonies of non-recombinant bacteria because of (a) insertional inactivation of alpha galactosidase in recombinant bacteria (b) inactivation of glycosidase enzyme in recombinant bacteria (c) non-recombinant bacteria containing beta galactosidase (d) insertional inactivation of alpha galactosidase in non-recombinant bacteria.

Description : The colonies of recombinant bacteria appear white in contrast to blue colonies of non-recombinant bacteria because of (a) insertional inactivation of alpha galactosidase in recombinant ... beta galactosidase (d) insertional inactivation of alpha galactosidase in non-recombinant bacteria.

Last Answer : (c) non-recombinant bacteria containing beta galactosidase

Non-coding sequences in a gene are known as (A) Cistrons (B) Nonsense codons (C) Introns (D) Exons

Description : Non-coding sequences in a gene are known as (A) Cistrons (B) Nonsense codons (C) Introns (D) Exons

Last Answer : Answer : C

A point mutation occurs in a sex cell of an adult chimpanzee. The mutation is located on a gene responsible for the development of the eye. Which describes the most likely effect of this mutation?

Description : A point mutation occurs in a sex cell of an adult chimpanzee. The mutation is located on a gene responsible for the development of the eye. Which describes the most likely effect of this mutation?

Last Answer : The chimpanzee's offspring will have abnormal eyes.

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

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

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

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

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 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

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

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

.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

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

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