Gene Expression Lesson

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

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

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

• regulator
• repressor
• activator
• corepressor

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

• promoter
• repressor
• operator
• gene

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

• operator
• promoter
• enhancer
• origin

An operon consists of all the the following EXCEPT

• operator
• promoter
• regulatory gene
• genes of the operon

The lactase genes only become expressed if:

• lactose binds to the repressor
• lactose unbinds with the repressor

In the lac operon, the genes within the operon will be expressed if:

• lactose is absent in the cell
• lactose is present in the cell

The parts of a gene that do NOT code for amino acids in a protein are called

• introns
• exons
• codons
• anticodons

A chemical modification of DNA that makes that gene less likely to be expressed.

• methylation
• acetylation

Most gene regulation happens at which step along the way?

• translation
• transcription
• signal transduction
• DNA replication