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Which of the following statements concerning the regulator gene (R) associated with the lac operon is correct? A) mRNA is transcribed from the R gene whether lactose is present or not. B) mRNA is transcribed from the R gene only when lactose is present. C) mRNA is transcribed from the R gene only when lactose is not present. D)Lactose inhibits the translation of R gene mRNA.?
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Most Upvoted Answer
Which of the following statements concerning the regulator gene (R) as...
Lactose interacts with the repressor protein (which binds onto operator region).. thereby unmasking the site for transcription...the repressor protein is inactivated... so there can be transcription only if lactose is there... (it is carbon source... other sources too can be used...)
Community Answer
Which of the following statements concerning the regulator gene (R) as...
Regulator Gene (R) Associated with the Lac Operon

The lac operon is a gene system in bacteria that consists of three structural genes (lacZ, lacY, and lacA), a promoter region, and an operator region. The regulator gene (R) is also associated with the lac operon and encodes a repressor protein that can bind to the operator region and prevent transcription of the structural genes. The regulator gene is important for regulating the expression of the lac operon in response to the presence or absence of lactose.

Correct Statement about Regulator Gene (R)

B) mRNA is transcribed from the R gene only when lactose is present.

Explanation

The regulator gene (R) is transcribed into mRNA regardless of whether lactose is present or not. However, the mRNA produced from the R gene is translated into a repressor protein that can bind to the operator region of the lac operon and prevent transcription of the structural genes. When lactose is present, it binds to the repressor protein and causes a conformational change that makes it unable to bind to the operator region. This allows RNA polymerase to bind to the promoter region and initiate transcription of the structural genes.

In summary, the regulator gene (R) associated with the lac operon is transcribed into mRNA all the time, but the translated repressor protein only allows transcription of the structural genes when lactose is absent. When lactose is present, it binds to the repressor protein and prevents it from binding to the operator region, allowing transcription to occur.
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Which of the following statements concerning the regulator gene (R) associated with the lac operon is correct? A) mRNA is transcribed from the R gene whether lactose is present or not. B) mRNA is transcribed from the R gene only when lactose is present. C) mRNA is transcribed from the R gene only when lactose is not present. D)Lactose inhibits the translation of R gene mRNA.?
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Which of the following statements concerning the regulator gene (R) associated with the lac operon is correct? A) mRNA is transcribed from the R gene whether lactose is present or not. B) mRNA is transcribed from the R gene only when lactose is present. C) mRNA is transcribed from the R gene only when lactose is not present. D)Lactose inhibits the translation of R gene mRNA.? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about Which of the following statements concerning the regulator gene (R) associated with the lac operon is correct? A) mRNA is transcribed from the R gene whether lactose is present or not. B) mRNA is transcribed from the R gene only when lactose is present. C) mRNA is transcribed from the R gene only when lactose is not present. D)Lactose inhibits the translation of R gene mRNA.? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the following statements concerning the regulator gene (R) associated with the lac operon is correct? A) mRNA is transcribed from the R gene whether lactose is present or not. B) mRNA is transcribed from the R gene only when lactose is present. C) mRNA is transcribed from the R gene only when lactose is not present. D)Lactose inhibits the translation of R gene mRNA.?.
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