Mutations, Electrophoresis, Gene Regulation

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

The lac operon genes only become expressed if:

• lactose binds to the repressor
• glucose binds to the repressor
• lactose binds to the operator
• the repressor binds to the operator

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

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

Repressible negative control is when when the gene is transcribed by the ____ of a specific molecule

• presence
• absence

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

• inducible
• repressible
• positive control
• promoible

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.