Operons

what is an operon?

• a part of a ribsome

• a long piece of mRNA for several proteins

• a unit of DNA containing linked genes that code for proteins needed to do a specific task

• sequence of DNA needed for DNA replication

What is the name of the stretch of DNA on an operon where RNA polymerase binds to initiate transcription?

• operator

• promoter

• enhancer

• origin

The location of an operon that functions as an "on/off" switch and is where a repressor would bind

• promoter

• repressor

• operator

• structural gene

Which of the following describes an operon that is inactive and becomes activated by a molecule binding to the repressor?

• inducible operon

• repressible operon

Which of the following describes an operon that is active and becomes inactivated by a molecule binding to the repressor?

• inducible operon

• repressible operon

A protein that binds to the operator and blocks the RNA polymerase

• inducer protein

• repressor protein

• activator protein

• structural protein

What types of cells have operons?

• Eukaryotes

• Prokaryotes

• Neither eukaryotes nor prokaryotes

• Both eukaryotes and prokaryotes

Where does the repressor in an operon bind?

• Operator

• Promoter

• Regulatory sequence

• TATA box

If the repressor is bound to the operator…

• RNA polymerase is able to bind, the operon is off

• RNA polymerase is able to bind, the operon is on

• RNA polymerase is unable to bind, the operon is off

• RNA polymerase is unable to bind, the operon is on

The lac operon is…

• Inducible operon so starts off and is activated by lactose

• Inducible operon so starts on and is deactivated by lactose

• Repressible operon so starts off and is activated by lactose

• Repressible operon so starts on and is deactivated by lactose