Operon

In negatively regulated operon the bound repressor will

• inhibit transcription

• Enhance the activity of RNA polymerase

• Facilitate transcription

• Decrease the enzymatic ectivity of RNA polymerase

Which of these operons is anabolic?

• Lac

• Ara

• Trp

• Phe

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

A Lac repressor is a tetramer repressed when bound to the inducer. The trp repressor is a ____________________

• Dimer inactivated when bound to the inducer

• Dimer activated on inducer binding

• Tetramer inactivated on inducer binding

• Tetramer activated on inducer binding

Operons are found in which of the following organisms?

• Bacteria(prokaryotes)

• plants and animals(eukaryotes)

• only animals

• virsuses

An operon consists of all the the following EXCEPT

• operator

• promoter

• regulatory gene

• genes of the operon

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

• Low

• Medium

• High

• Very high

We know that lactose has a positive impact on the activity of the lac operon. Tryptophan’s presence has a ________________

• Positive feedback

• Negative feedback

• No difference

• Highly positive impact

Tags

NGSS.HS-LS1-3

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