Prokaryotic Gene Expression

How can a person's muscle cells have the same exact DNA sequences as their nerve cells even though they look and perform completely different?

• The two different cells become mutated

• The proteins expressed in each cell are different

• They actually have different DNA in the two types of cells.

• The genome of the different cells changes

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

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

• promoter
• repressor
• operator
• gene

what does a promoter do?

• it allows RNA polymerase to bind so that a gene can be transcribed

• it creates a DNA segment

• it turns genes on and off

• it is the gene that makes the repressor

What is an operon?

• the genes used for gene regulation in eukaryotic cells

• the DNA where RNA Polymerase binds to DNA

• a unit made up of a promotor, an operator and DNA that code for proteins needed to do a specific task

• a gene needed for dna replication

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

• regulator

• repressor

• activator

• corepressor

A small molecule that binds to the repressor and makes it inactive is

• corepressor

• inducer

• promoter

• operator

Most all cells in an organism have the same DNA, but different genes are active in different cells.

• True

• False

Differentiate between an inducible operon and a repressible operon.

• Inducible operons are usually on, while repressible operons are usually off.

• Inducible operons are usually off, while repressible operons are usually on.

At what point of protein synthesis does gene regulation occur in prokaryotic cells?

• before transcription

• before translation

• after translation

• before RNA modification