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Read the following and answer the question given below:
The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.
Which of the following statements is true in reference to the lac operon process in E.coli?
(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNA
- a)Only i is correct
- b)Only ii is correct
- c)Both (i) and (ii) are correct
- d)None of them are correct
Correct answer is option 'B'. Can you explain this answer?
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Verified Answer
Read the following and answer the question given below:The lac operon...
The messenger RNA produced by transcription carries information for the synthesis of all three proteins found in all three structural genes. Hence, it is a polycistronic messenger RNA.
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Read the following and answer the question given below:The lac operon...
Explanation:
The lac operon is a system of genes involved in the metabolism of lactose in E.coli. It consists of a regulator gene, a promoter region, an operator region, and three structural genes: lacZ, lacY, and lacA.
Regulation of lac operon:
- The lac operon is regulated by a repressor protein produced by the regulator gene.
- In the absence of lactose, the repressor protein binds to the operator region, preventing RNA polymerase from transcribing the structural genes.
- When lactose is present, it acts as an inducer. Lactose binds to the repressor protein, causing a conformational change that prevents it from binding to the operator region.
- As a result, RNA polymerase can access the promoter region and transcribe the structural genes.
Statement (i): Galactosidase is the only enzyme produced in large quantities when lac operon is turned on.
- This statement is incorrect. The lac operon is responsible for the production of three enzymes: beta-galactosidase (lacZ), lactose permease (lacY), and thiogalactoside transacetylase (lacA).
- Beta-galactosidase is involved in the hydrolysis of lactose into glucose and galactose.
- Lactose permease facilitates the transport of lactose into the cell.
- Thiogalactoside transacetylase is involved in the detoxification of certain lactose analogs.
Statement (ii): The messenger RNA in lac operon is a polycistronic mRNA.
- This statement is correct. A polycistronic mRNA is an mRNA molecule that contains the coding sequences for multiple genes.
- In the lac operon, a single mRNA molecule is transcribed from the promoter region, and this mRNA contains the coding sequences for all three structural genes (lacZ, lacY, and lacA).
- The polycistronic mRNA is then translated into individual proteins by ribosomes.
Conclusion:
- From the given options, only statement (ii) is correct. The messenger RNA in lac operon is a polycistronic mRNA.
- Statement (i) is incorrect as the lac operon produces three enzymes, not just galactosidase.
- Therefore, the correct answer is option B.
The lac operon is a system of genes involved in the metabolism of lactose in E.coli. It consists of a regulator gene, a promoter region, an operator region, and three structural genes: lacZ, lacY, and lacA.
Regulation of lac operon:
- The lac operon is regulated by a repressor protein produced by the regulator gene.
- In the absence of lactose, the repressor protein binds to the operator region, preventing RNA polymerase from transcribing the structural genes.
- When lactose is present, it acts as an inducer. Lactose binds to the repressor protein, causing a conformational change that prevents it from binding to the operator region.
- As a result, RNA polymerase can access the promoter region and transcribe the structural genes.
Statement (i): Galactosidase is the only enzyme produced in large quantities when lac operon is turned on.
- This statement is incorrect. The lac operon is responsible for the production of three enzymes: beta-galactosidase (lacZ), lactose permease (lacY), and thiogalactoside transacetylase (lacA).
- Beta-galactosidase is involved in the hydrolysis of lactose into glucose and galactose.
- Lactose permease facilitates the transport of lactose into the cell.
- Thiogalactoside transacetylase is involved in the detoxification of certain lactose analogs.
Statement (ii): The messenger RNA in lac operon is a polycistronic mRNA.
- This statement is correct. A polycistronic mRNA is an mRNA molecule that contains the coding sequences for multiple genes.
- In the lac operon, a single mRNA molecule is transcribed from the promoter region, and this mRNA contains the coding sequences for all three structural genes (lacZ, lacY, and lacA).
- The polycistronic mRNA is then translated into individual proteins by ribosomes.
Conclusion:
- From the given options, only statement (ii) is correct. The messenger RNA in lac operon is a polycistronic mRNA.
- Statement (i) is incorrect as the lac operon produces three enzymes, not just galactosidase.
- Therefore, the correct answer is option B.
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Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer?
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Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer?.
Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer?.
Solutions for Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for NEET.
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Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of Read the following and answer the question given below:The lac operon consists of a regulation gene and three structural genes. The lactose acts as an inducer. In the presence of an Inducer such as lactose, the repressor is inactivated during the interaction. This allows RNA polymerase access to the promoter and transcription proceeds. The repressor is synthesized which in turn binds with the operator region of the operon and prevents RNA polymerase from transcribing the operon.Which of the following statements is true in reference to the lac operon process in E.coli?(i) Galactosidase is the only enzyme produced in large quantities when lac operon is turned on (ii) The messenger RNA in lac operon is a polycistronic mRNAa)Only i is correctb)Only ii is correctc)Both (i) and (ii) are correctd)None of them are correctCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an
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