Exam (elaborations)
ASU BIO 340 Exam 3 Questions and Complete Solutions Graded A+
- Course
- Institution
ASU BIO 340 Exam 3 Questions and Complete Solutions Graded A+
[Show more]
Content preview
ASU BIO 340 Exam3 Questions and
Complete Solutions
Graded A+
Denning [Date] [Course title]
, What will be the effect on transcription when an inhibitor is in play?
A. Allow transcription B. Prevent transcription - Correct Ans: B Explanation: An inhibitor prevents
activator from binding to DNA; activators are used in positive regulation (increasing transcription) - thus,
the inhibitor prevents the activator from positive regulating (increasing) transcription.
What will be the effect on transcription when an inducer is in play?
A. Allow transcription B. Prevent transcription - Correct Ans: A Explanation: When an inducer is in play,
it will allow transcription.
For a gene under positive control, which of the following would prevent transcription?
A. Repressor B. Corepressor C. Inducer D. Effector E. Inhibitor - Correct Ans: E Explanation: Positive
regulation includes activators (affected by effectors and inhibitors); inhibitors prevent activator from
binding to DNA, thus preventing transcription.
For a gene under negative control, which of the following would you expect to find bound to the
repressor if there is active transcription? A. Repressor B. Corepressor C. Inducer D. Effector E. Inhibitor -
Correct Ans: C Explanation: In negative regulation, there are repressors (affected by correpressors and
inducers). If there were a corepressor, the repressor would successfully bind to the operator and
prevent transcription. Inducers, however, prevent the binding of the repressor - thus causing a
prevention of it doing its job, and allowing transcription.
Which molecule serves as the inducer for the lac operon?
A. cAMP B. Glucose C. Lactose D. Allolactose - Correct Ans: D Explanation: Allolactose is the molecule
that binds to repressor protein, making it unable to bind to the operator.
Which of the following conditions will result in the greatest levels of transcription of the lac operon?
A. Lactose absent, glucose absent B. Lactose absent, glucose present C. Lactose present, glucose present
D. Lactose present, glucose absen - Correct Ans: D Explanation: From the perspective of the cell, it is
most efficient to repress expression of the genes allowing for metabolism of lactose when it's absent, to
allow it when present, but only to prioritize it when glucose (the preferred food source) is absent. In C,
allolactose will also be present, allowing transcription, but positive regulation (i.e. increase in
transcription) only happens as in D, when glucose is absent.
Which of the following mutations will result in the lowest level of transcription of the lac operon when
lactose is present?
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller YourExamplug. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
81531 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now