n an inducible operon, the genes are (a) usually not expressed unless a signal turns them”on”. (b) usually expressed unless a signal turns them “off”. (c) never expressed (d) always expresser.

n an inducible operon, the genes are
(a) usually not expressed unless a signal turns
them”on”.
(b) usually expressed unless a signal turns them “off”.
(c) never expressed
(d) always expresser.
by

1 Answer

Answer :

(a) usually not expressed unless a signal turns
them”on”.
by

Related questions

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 lac operon is an example of (a) repressible operon (b) overlapping genes (c) arabinose operon (d) inducible operon.

Description : The lac operon is an example of (a) repressible operon (b) overlapping genes (c) arabinose operon (d) inducible operon.

Last Answer : (d) inducible operon.

An example of an inducible group of genes is the ______. a. ARG operon b. NAC operon c. LAC operon d. SAC operon

Description : An example of an inducible group of genes is the ______. a. ARG operon b. NAC operon c. LAC operon d. SAC operon

Last Answer : c. LAC operon

.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.

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

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

Explain an inducible operon. -Biology

Description : Explain an inducible operon. -Biology

Last Answer : answer:

Why is the lac operon said to be an inducible operon? -Biology

Description : Why is the lac operon said to be an inducible operon? -Biology

Last Answer : answer:

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 recessive genes located on X-chromosome humans are always (a) lethal (b) sub-lethal (c) expressed in males (d) expressed in females.

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Last Answer : (c) expressed in males

What genes are parts of the lac operon? -Biology

Description : What genes are parts of the lac operon? -Biology

Last Answer : answer:

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

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Last Answer : Answer : B

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

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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

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Last Answer : Answer : D

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

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

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

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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

Lac operon is a cluster of genes present in (A) Human beings (B) E. coli (C) Lambda phage (D) All of these

Description : Lac operon is a cluster of genes present in (A) Human beings (B) E. coli (C) Lambda phage (D) All of these

Last Answer : Answer : B

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

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Last Answer : Answer : B

A group of genes whose activity is coordinated by a DNA site is – (1) operon (2) cistron (3) polysome (4) polypeptide

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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.

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.All of the following are part of an operon except (a) an operator (b) structural genes (c) an enhancer (d) a promoter.

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

.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.

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

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.

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

All of the following are part of an operon except (a) an operator (b) structural genes (c) an enhancer (d) a promoter.

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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)

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In bacteria a group of genes located together and functioning together on a chromosome are called _____a. polysome b. operon c. polymerase d. exons.

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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

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The structural genes of lac operon transcribe mRNA which is a) polycistronic b) replicative c) monokaryotic d) monocistronic

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A group of genes whose activity is coordinated by a DNA site is called: (1) operon (2) cistron (3) polysome (4) polypeptide

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Last Answer : operon

Enzymes which are always present in an organism are known as (A) Inducible enzymes (B) Constitutive enzymes (C) Functional enzymes (D) Apoenzymes

Description : Enzymes which are always present in an organism are known as (A) Inducible enzymes (B) Constitutive enzymes (C) Functional enzymes (D) Apoenzymes

Last Answer : Answer : B

It's always 1 to 6, it's always 15 to 20, it's always 5, but it's never 21, unless it's flying.What is it? -Riddles

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Last Answer : The answer is: a dice. An explanation: 'It's always 1 to 6': the numbers on the faces of the dice, 'it's always 15 to 20': the sum of the exposed faces when the dice comes to rest after being thrown, 'it's ... the sum of all exposed faces when the dice is flying is 21 (1 + 2 + 3 + 4 + 5 + 6).

Indicate the false statement. Noise figure is defined as A. the ratio of the S/N power supplied at the input terminal of a receiver or amplifier to the S/N power supplied to the output or load resistor B. noise factor expressed in decibels C. an unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signal D. S/N of an ideal system divided by S/N at the output of the receiver or amplifier under test, both working at the same temperature over the same bandwidth and fed from the same source

Description : Indicate the false statement. Noise figure is defined as A. the ratio of the S/N power supplied at the input terminal of a receiver or amplifier to the S/N power supplied to the output or ... under test, both working at the same temperature over the same bandwidth and fed from the same source

Last Answer : C. an unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signals

Why Was I Always Taught That Once A Kick off Went 10 Yards It Was A Free Ball Unless It Went Out Of Bounds. I have Seen At Least 2 College Games Where The Ball Went Into The End Zone Untouched And Did?

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Last Answer : There are two separate kicks (not including punts) in football,the scrimmage kick and the on-sides kick.The scrimmage kick is also known as the kickoff. A Kickoffoccurs at the start of each ... goesout of bounds, the Receiving team retains possession at the spotwhere the ball goes out of bounds.

.Expressed Sequence Tags (ESTs) refers to (a) novel DNA sequences (b) genes expressed as RNA (c) polypeptide expression (d) DNA polymorphism.

Description : .Expressed Sequence Tags (ESTs) refers to (a) novel DNA sequences (b) genes expressed as RNA (c) polypeptide expression (d) DNA polymorphism.

Last Answer : (b) genes expressed as RNA

With regard to HLA class 1 antigen: a. they are expressed on all nucleated cells b. they are essential for viral antigen recognition by cytotoxic cells c. the genes for HLA class 1 molecules are located on chromosome 6 and 15 d. all above

Description : With regard to HLA class 1 antigen: a. they are expressed on all nucleated cells b. they are essential for viral antigen recognition by cytotoxic cells c. the genes for HLA class 1 molecules are located on chromosome 6 and 15 d. all above

Last Answer : all above

The following are true : a. the HLA proteins are found within the cytoplasm of the cells b. HLA class I antigens are expressed on all cells with nuclei c. HLA class II antigens presents the virus infected cells to cytotoxic T lymphocytes d. HLA genes are found on chromosome 6 e. HLA tissue typing is carried out in all forms of transplantation to prevent rejection

Description : The following are true : a. the HLA proteins are found within the cytoplasm of the cells b. HLA class I antigens are expressed on all cells with nuclei c. HLA class II antigens presents ... on chromosome 6 e. HLA tissue typing is carried out in all forms of transplantation to prevent rejection

Last Answer : HLA class I antigens are expressed on all cells with nuclei

What map unit (centimorgan) is adopted in the construction of genetic maps? (a) A unit of distance between genes on chromosomes, representing 50% cross over. (b) A unit of distance between two expressed genes, representing 10% cross over. (c) A unit of distance between two expressed genes, representing 100% cross over. (d) A unit of distance between genes on chromosomes, representing 1% cross over.

Description : What map unit (centimorgan) is adopted in the construction of genetic maps? (a) A unit of distance between genes on chromosomes, representing 50% cross over. (b) A unit of distance between two ... 100% cross over. (d) A unit of distance between genes on chromosomes, representing 1% cross over.

Last Answer : (d) A unit of distance between genes on chromosomes, representing 1% cross over.

Are all genes expressed at the same time in all cell types?

Description : Are all genes expressed at the same time in all cell types?

Last Answer : No- genes are expressed at different times or in different cells types. There are several sequences in DNA that regulate when a genes is transcribed, such as- promoters and enhancer ... to start transcription and operator sequences that allow for external proteins to cause activation or repression.

A pair of current-carrying conductors is not considered a transmission line unless it is at least ___ λ long at the signal frequency. A. 0.1 B. 0.3 C. 0.2 D. 0.4

Description : A pair of current-carrying conductors is not considered a transmission line unless it is at least ___ λ long at the signal frequency. A. 0.1 B. 0.3 C. 0.2 D. 0.4

Last Answer : A. 0.1

I purge all that is evil, and keep all that is true. Unless you speak, I can delete what you said. My usefulness has faded with the use of a pen. I am usually made of rubber, yet I am not a toy. I am both pink, and white, but also blue, or green. Do not forget me, as I can be your best friend. What am I? -Riddles

Description : I purge all that is evil, and keep all that is true. Unless you speak, I can delete what you said. My usefulness has faded with the use of a pen. I am usually made of rubber, yet I am not a toy. I ... , but also blue, or green. Do not forget me, as I can be your best friend. What am I? -Riddles

Last Answer : An eraser.

I'm made for one but meant for two;I can be worn for many years but usually just a few;You won't ever need me unless you say you do.What am I? -Riddles

Description : I'm made for one but meant for two;I can be worn for many years but usually just a few;You won't ever need me unless you say you do.What am I? -Riddles

Last Answer : A Wedding ring.

Gas is usually not liberated due to dissociation of transformer oil unless the oil temperature exceeds?

Last Answer : Gas is usually not liberated due to dissociation of transformer oil unless the oil temperature exceeds 150°C.

The distinctive feature of the isoenzyme cyclooxygenase-2 is (a) It is not inhibited by indomethacin (b) It is inducible (c) It generates cytoprotective prostagladins in gastric mucosa (d) It is found only in foetal tissues

Description : The distinctive feature of the isoenzyme cyclooxygenase-2 is (a) It is not inhibited by indomethacin (b) It is inducible (c) It generates cytoprotective prostagladins in gastric mucosa (d) It is found only in foetal tissues

Last Answer : Ans: B

Aspirin in low doses produces longlasting inhibition (a) Platelets contain low quantity of COX (b) Platelets cannot synthesize fresh COX molecules (c) Platelets bind aspirin with high affinity (d) Platelet COX is inducible

Description : Aspirin in low doses produces longlasting inhibition (a) Platelets contain low quantity of COX (b) Platelets cannot synthesize fresh COX molecules (c) Platelets bind aspirin with high affinity (d) Platelet COX is inducible

Last Answer : Ans: B

The cyclooxygenase isoenzymes COX-1 and COX-2 differ from each other in that (a) They catalyse different pathways in prostanoid biosynthesis (b) COX–1 is inhibited by aspirin but not COX–2 (c) COX–2 is inhibited by ibuprofen but not COX–1 (d) COX–1 is constitutive while COX–2 is inducible

Description : The cyclooxygenase isoenzymes COX-1 and COX-2 differ from each other in that (a) They catalyse different pathways in prostanoid biosynthesis (b) COX–1 is inhibited by aspirin but not COX–2 (c) COX–2 is inhibited by ibuprofen but not COX–1 (d) COX–1 is constitutive while COX–2 is inducible

Last Answer : Ans: D

Acquisition of inducible energy dependent efflux proteins by bacteria serves to: A. Secrete exotoxins B. Enhance virulance C. Lyse host tissue D. Confer antibiotic resistance

Description : Acquisition of inducible energy dependent efflux proteins by bacteria serves to: A. Secrete exotoxins B. Enhance virulance C. Lyse host tissue D. Confer antibiotic resistance

Last Answer : D. Confer antibiotic resistance