Lac Operon Quiz ChallengeOnline version Test your knowledge on the lac operon and its role in gene regulation! by Sirajunnisa Razack 1 What is the primary function of the lac operon? a To regulate lactose metabolism in bacteria. b To produce energy. c To synthesize proteins. d To replicate DNA. 2 Which sugar does the lac operon primarily respond to? a Lactose. b Glucose. c Fructose. d Sucrose. 3 What is the role of the lac repressor in the lac operon? a It degrades RNA. b It binds to glucose. c It inhibits transcription in the absence of lactose. d It activates transcription. 4 What happens when lactose is present in the lac operon? a The operon is deleted. b Transcription is permanently blocked. c Lactose binds to the repressor, allowing transcription. d Only glucose is metabolized. 5 Which genes are part of the lac operon? a lacC, lacD, and lacH. b lacE, lacF, and lacG. c lacP, lacQ, and lacR. d lacZ, lacY, and lacA. 6 What does lacZ encode? a Lactose permease. b Transacetylase. c Beta-galactosidase. d Glucose kinase. 7 What is the effect of glucose on the lac operon? a It destroys the operon. b It inhibits the operon through catabolite repression. c It has no effect. d It activates the operon. 8 What is the function of lacY? a It encodes glucose transporter. b It encodes beta-galactosidase. c It encodes lactose permease, facilitating lactose entry. d It encodes transacetylase. 9 What is the role of cyclic AMP (cAMP) in the lac operon? a It synthesizes glucose. b It inhibits the repressor. c It activates CAP, enhancing RNA polymerase binding. d It degrades lactose. 10 What type of regulation is the lac operon an example of? a Negative and positive regulation. b Only negative regulation. c No regulation. d Only positive regulation.
