6.3 & 6.4 - Regulation of Gene Expression & Mutations

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

• regulator
• repressor
• activator
• corepressor

Operons are found in the cells of which of the following types of organisms?

• prokaryotes (bacteria)
• eukaryotes (plant and animals)
• animals only
• viruses

What is 1 in the diagram?

• RNA polymerase

• Inducer

• Repressor

• Operator

What is 2 in the diagram?

• RNA polymerase

• Inducer

• Repressor

• Operator

What is 4 in the diagram?

• RNA polymerase

• Inducer

• Repressor

• Operator

What is 5 in the diagram?

• RNA polymerase

• Inducer

• Repressor

• Operator

In the top picture the operon is

• on

• off

In the bottom picture the operon is

• on

• off

What type of operon is the trp (tryptophan) operon?

• inducible

• repressible

• positive control

• promoible

The tryptophan operon is

• permanently turned on.

• turned on when tryptophan is present in the growth medium.

• turned off only when glucose is present in the growth medium.

• turned off when tryptophan is added to the growth medium.