Deck 13: Gene Regulation

Question 1

Some genes such as that for b-actin are expressed at relatively constant levels in tissues regardless of variations in the animal's condition. What do we call this type of gene?

A) transposable element
B) steady state gene
C) constitutive gene
D) recombinant gene
E) multifunctional gene

Answer 1

constitutive gene

Question 2

Which of the following could alter the level of expression of a gene?

A) an increase in environmental temperature
B) an increase in salinity
C) exposure to UV radiation
D) presence of a particular energy substrate
E) All of the choices are correct.

Answer 2

All of the choices are correct.

Question 3

Which of the following are points of control for gene expression in eukaryotes?

A) RNA processing
B) translation
C) transcription
D) post-translational
E) All of the choices are correct.

Answer 3

All of the choices are correct.

Question 4

Which of the following statements is TRUE of small effector molecules?

A) Small effector molecules cause a conformational change in a regulatory protein.
B) Small effector molecules can prevent a repressor from binding a gene region.
C) Small effector molecules regulate gene transcription.
D) Small effector molecules regulate gene transcription by binding a regulatory protein.
E) All of the choices are correct.

Question 5

Why is the operon arrangement of genes beneficial to certain bacteria?

A) It allows for the differential regulation of individual genes that encode proteins with a common function.
B) It allows the coordinated regulation of a group of genes that encode proteins with a common function.
C) It allows the separate regulation of individual genes that encode proteins with different functions.
D) It allows the coordinated regulation of a group of genes that encode proteins with different functions.
E) It allows for coordinated regulation of a group of proteins involved in numerous cellular activities.

Question 6

Once the lac repressor binds to the lac operator site, RNA polymerase is prevented from transcribing which genes?

A) galactosidase gene
B) regulatory gene
C) galactoside transacetylase gene
D) galactosidase and galactoside transacetylase genes
E) galactosidase and regulatory genes

Question 7

Which of the following occurs when allolactose levels increase in E. coli?

A) Transcription of genes within the lac operon increases.
B) Transcription of genes within the lac operon decreases.
C) Transcription of genes within the lac operon does not change.
D) E. coli cells replicate rapidly.
E) The tryptophan operon becomes more active.

Question 8

Which of the following occurs in E. coli when lactose is absent from its environment?

A) Large amounts of b-galactosidase, lactose permease, and galactoside transacetylase are made.
B) Trace amounts of b-galactosidase, lactose permease, and galactoside transacetylase are made.
C) No b-galactosidase, lactose permease, and galactoside transacetylase is made.
D) The lac operon is induced.
E) Polycistronic mRNA levels would be very high.

Question 9

strain of bacteria containing F? factor genes is called a

A) monozygote.
B) heterozygote.
C) homozygote.
D) merozygote.
E) hemizygote.

Question 10

Jacob, Monod, and Pardee constructed a mutant strain of E. coli that carried a lacI-gene mutation (encodes the lac repressor). Which is TRUE of this mutant strain?

A) Trancription of the lac operon is repressed.
B) Trancription of the lac operon does not change.
C) The lac operon is constitutively expressed.
D) Nonfunctional proteins are produced.
E) The lac operon is constitutively expressed and nonfunctional proteins are produced

Question 11

The lac operator site within the lac operon is an example of which of the following?

A) cis-acting element
B) para-acting element
C) trans-acting element
D) inter-acting element
E) contra-acting element

Question 12

Where is the response element found in eukaryotic genes?

A) 10 to 20 base pairs downstream from the transcriptional start site
B) 50 to 100 base pairs downstream from the transcriptional start site
C) 50 to 100 base pairs upstream from the transcriptional start site
D) 10 to 20 base pairs upstream from the TATA box
E) 500 to 10,000 base pairs from the enhancer site

Question 13

Which of the following protein(s) does NOT play a role in initiating transcription in eukaryotes?

A) general transcription factors
B) transposase
C) RNA polymerase II
D) mediator
E) general transcription factors and RNA polymerase II

Question 14

Which of the following is TRUE of the mediator protein complex in eukaryotes?

A) Mediator facilitates interactions between RNA polymerase II and regulatory transcription factors.
B) Mediator controls the rate at which RNA polymerase transcribes mRNA.
C) Mediator partially wraps around RNA polymerase and the general transcription factors.
D) Mediator is composed of several proteins.
E) All of the choices are correct.

Question 15

Which of the following is NOT a motif structure commonly found in transcription factor proteins?

A) helix-turn-helix motif
B) helix-loop-helix motif
C) zinc finger motif
D) arginine helix-loop-zipper motif
E) leucine zipper motif

Question 16

Which of the following does NOT occur during transcriptional regulation in eukaryotes?

A) Chromatin is converted to the closed conformation.
B) The gene must be transcribed.
C) The RNA must be processed and exported from the nucleus.
D) The protein must be made via translation.
E) Chromatin is converted to the open conformation.

Question 17

Which of the following is NOT true of the glucocorticoid receptor?

A) The receptor contains a nuclear localization signal (NLS).
B) When bound to glucocorticoids, the receptors will bind covalently and irreversibly to each other to form dimers.
C) Glucocorticoid receptor dimers bind glucocorticoid response elements (GREs).
D) Binding of glucocorticoid receptor dimers to GREs activates the transcription of the adjacent gene.
E) The receptor contains a binding domain for glucocorticoids.

Question 18

RNA polymerase can bind to the promoter region of the DNA even when the lac repressor is bound to the operator site.

Question 19

A cis-effect is a form of gene regulation that can occur between two DNA segments that are not physically adjacent.

Question 20

Alternative versions of proteins often have similar functions.