Are you looking for Mcqs on Lac operon? If Yes then you are at right place. Here you will find Lac operon Mcq Questions and Answers, Trivia, Quiz, Interview MCQ & Lac operon Current Affairs for Competitive Exams like Neet exams, around 30% to 40% of Neet questions are asked from given Lac operon Mcqs. as you know Questions and Ansers on Lac operon is very important for Neet Exam. In this Lac operon MCQ section for Neet competition we are covering MCQS on Lac operon
Question : The correct option regarding the lac operon in E.coli from the following is
A. Lac operon is switched on in the absence of lactose
B. Lac repressor binds to the lac promoter
C. β-galactosidase is the only enzyme produced in large quantities when lac operon is turned on
D. lac operon messenger RNA is a polycistronic mRNA
Question : This condition in lac operon facilitates the condition of lac genes being transcribed at high levels
A. low glucose, high lactose
B. low glucose, low lactose
C. high glucose, high lactose
D. high glucose, low lactose
Question : In Lac-operon, the gene product of LacA gene is
A. Beta-galactoside permease
B. Beta-galactoside transacetylase
C. Beta-galactosidase
D. Beta-galactoside isomerase
Question : This will be prevented if the activator fastens to the repressor
A. Transcription
B. Binding of the RNA polymerase to the promoter
C. Binding of the repressor to the operator
D. Binding of the repressor to the promoter
Question : Lac Operon will be turned on when
A. Lactose is less than glucose
B. Lactose is less in the medium
C. Lactose in more than glucose
D. Glucose is enough in the medium
Question : Regulation of the lac operon can be envisioned as regulation of enzyme synthesis by its
A. lactose
B. substrate
C. carbohydrates
D. all of the above
Question : The sequence of the structural genes in the lac operon is
A. lacA-lacZ-lacY
B. lacZ-lacY-lacA
C. lacZ-lacA-lacY
D. lacA-lacY-lacZ
Question : Which of these acts as an inducer of the lac operon?
A. Allolactose
B. Lactose
C. Galactose
D. Glucose
Question : In the presence of lactose, how long does it take for the lac operon to be expressed?
A. when lactose equals glucose concentration
B. when glucose is more than lactose concentration
C. as long as lactose is more than glucose concentration
D. as long as lactose is more than galactose concentration
Question : Lac operon is an example of
A. only positive regulation
B. only negative regulation
C. both positive and negative regulation
D. sometimes positive sometimes negative