LAC OPERON

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

In the lac operon the inducer is

• allolactose

• glucose

• galactose

• all of the above

The sequence where lac repressor binds on operon is called_______

• promoter

• lac z

• operator

• lac I

Which of the following is not a structural gene?

• lac z

• lac y

• lac a

• lac I

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

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

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

What does the lactose do to the Operon?

• Blocks transcription because of the energy it provides

• Allows the repressor to be unbinded from the Operator.

• The lactose binds to the lactose and stops transcription

• Allows for the transcription to speed up