Gene Expression

An operon consists of all the the following EXCEPT

• operator

• promoter

• regulatory gene

• genes of the operon

Operons are found in which of the following organisms?

• Bacteria(prokaryotes)

• plants and animals(eukaryotes)

• only animals

• virsuses

The "on/off" switch for an operon is called the

• promoter

• repressor

• operator

• gene

What does a promoter do?

• binds RNA polymerase for transcription

• binds DNA polymerase for replication

• binds the operator

• binds the repressor

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

• regulator

• repressor

• activator

• corepressor

The lac operon genes only become expressed if:

• lactose binds to repressor

• glucose binds to repressor

• repressor binds to operator

• lactose binds to operator

Most gene regulation happens at which step along the way?

• translation

• transcription

• signal transduction

• DNA replication

What is the name of the stretch of DNA where RNA polymerase binds?

• operator

• promoter

• enhancer

• regulatory gene

What does the lactose do to the Operon?

• Blocks transcription of the lactase gene by cutting up the DNA

• Binds to the repressor preventing it from attaching to the operator

• The lactose binds promoter to prevent transcription

• Allows for the transcription rate of lactase to slow down

In a repressible operon, the corepressor

• allows transcription to progress

• allow the repressor to prevent transcription

• binds to the promoter and transcribes the gene