operon

What is another name for a "regulatory protein?"

• Promoter

• Gene

• repressor

• Corepressor

What is produced by a regulatory gene?

• A regulatory protein that binds to the regulatory sequence

• Nothing

• A regulatory sequence that binds to the regulatory gene

What is the process called by which DNA makes a copy of itself into RNA?

• Replication

• Translation

• Transcription

What is the process called by which ribosomes turn the code in RNA into an amino acid sequence (and ultimately a protein)?

• Translation

• Trascription

• Replication

When does most gene regulation take place?

• After translation

• Before transcription

• After transcription

• Immediately before translation

Where does RNA polymerase bind the DNA?

• anywhere is good.

• On one of the lac genes.

• On the promoter.  

___________ is like a switch that can be in the off or on position.

• operator

• repressor

• promotor

The Lac operon is in the "off" position when

• It is always on.

• Lactose is absent

• lactose is present

How does the repressor "know" when lactose is present?

• The absence of lactose changes the shape of the repressor so it no longer fits in the operator.

• Lactose binds and it changes the shape of the repressor so it no longer fits in the operator

Why would the repressor be active (blocking RNA pol) in the presence of Tryptophan?

• There is no need to make Tryptophan if it is present in the environment. It is a waste of energy and resources. 

   

• Tryptophan is lethal to the bacteria cell. 

Tags

NGSS.HS-LS1-3