Tryptophan operon

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

Which of these systems give the best mode for turning trp operon off?

• Repressor

• Attenuator

• Repressor with a downstream poly A tail

• Repressor with an attenuator

When uncharged tRNA concentration is low what will you expect as the activity of tryptophan operon?

• Low

• Medium

• High

• Very high

Which segments of the attenuator together form the repression loop?

• Segment 1-2

• Segment 2-3

• Segment 3-4

• Segment 1-4

Which of these properties do not agree with trp operon attenuator?

• It brings about repression of trp operon

• It consists of one stem loop system

• It has two codons for tryptophan in sequence

• Ribosome stalls at the attenuator

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

• promoter

• enhancer

• operator

• gene

The tryptophan operon is

• permanently turned on.

• turned on when tryptophan is present in the growth medium.

• turned off only when glucose is present in the growth medium.

• turned off when tryptophan is added to the growth medium.

Tags

NGSS.HS-LS1-3

What does a promoter do?

• it allows a gene to be transcribed

• it creates a DNA segment

• it is another word for ribosomes

• it is another word for RNA

Structural genes of trp operon encodes for

• tryptophan synthetase

• tryptophan dioxygenase

• tryptophan kinase

• tryptophan polymerase