AP Biology Operons Review

what is an operon?

• a part of a ribsome
• a part of a Rna
• a unit made up of linked genes that code for proteins needed to do a specific task
• needed for dna replication

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

What is the role of operons in prokaryote gene expression?

• It makes the genes prokaryotes be turned on
• It accounts for the regulation of gene activity in response to the needs of the cells
• To make DNA for the gene
• To make the gene turn of and off

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

• inducible
• repressible
• positive control
• promoible

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

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

What does the lactose do to the Operon?

• Blocks transcription because of the energy it provides

• Allows the repressor to unbind from the Operator.

• The lactose binds the lactose and stops transcription

• Allows for the transcription to speed

For a repressible operon to be transcribed, which of the following must be true?

• A corepressor must be present.
• RNA polymerase and the active repressor must be present.
• RNA polymerase must bind to the promoter, and the repressor must be inactive.
• RNA polymerase cannot be present, and the repressor must be inactive.

Which molecule can we find the promoter and terminator in?

• DNA
• mRNA
• tRNA
• polypeptide chain