Intro to operons and trp operon

An operon consists of all of the following except:

• operator

• regulatory gene

• promoter

• genes of the operon

What does the repressor protein do?

• Allows RNA polymerase to read the gene
• Prevents RNA polymerase from reading the gene
• Reads the gene
• Translates the gene

Which of the following describes the type of pathway that a repressible operon controls?

• anabolic pathway

• catabolic pathway

In the trp operon, the tryptophan binds to the repressor. Which of the following is the term used to describe this molecule?

• inducer

• corepressor

• enhancer

• CAP

The trp operon is an example of an repressible operon. Which of the following describes the process that occurs when tryptophan is present?

• The tryptophan binds to the repressor which inactivates it and the repressor binds to the operator to turn translation off.

• The tryptophan binds to the repressor which activates it and the repressor releases from the operator to turn translation off.

• The tryptophan binds to the repressor which inactivates it and the repressor releases from the operator to turn translation off.

• The tryptophan binds to the repressor which activates it and the repressor binds to the operator to turn translation off.

Why are insertion and deletion mutations so harmful?

• They change all of the codons from the mutation on down the line, which changes the amino acid sequence
• They insert things that an organism doesn't need.
• They often delete things that organisms need.
• Insertion and deletions are not any more harmful than substitution mutations.

Tags

NGSS.HS-LS3-2

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

• inducible
• repressible
• positive control
• promoible

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

• inducer

• repressor

• activator

• corepressor

A key advantage of grouping genes with related functions is that a single "on-off" switch can control the whole cluster.

• True

• False

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

• promoter

• enhancer

• operator

• gene