Chapter 17 Gene Regulation in Eukaryotes Complete Test Bank

Genetics, 6e (Hartwell)

Chapter 17 Gene Regulation in Eukaryotes

1) Transcription in prokaryotes and eukaryotes is similar in that

A) transcriptional machinery controls the structure of chromatin.

B) the mRNA produced can undergo alternative splicing.

C) both are regulated by enhancers that can be located far away from the gene.

D) both occur within the cell nucleus.

E) both are regulated by binding of proteins to DNA near the gene being transcribed.

2) Which of these types of gene regulation occurs earliest in the process of gene expression?

A) alternative splicing

B) protein modification

C) export of mRNA to the cytoplasm

D) translation initiation

3) A protein with a zinc-finger domain most likely has what type of activity?

A) modifying proteins with phosphate groups

B) DNA binding

C) mRNA splicing

D) initiation of translation

4) DNA sequences that are binding sites for transcription factors are called

A) cross-reacting.

B) cis-acting elements.

C) trans-acting factors.

D) origins of transcription.

E) transcription factors.

5) What is the name of the cis-acting DNA sequence at which the transcriptional initiation complex forms?

A) promoter

B) terminator

C) enhancer

D) activator

E) transcription factor

6) What is the term for a cis-acting DNA sequence that may function at a distance from the gene they are regulating?

A) promoter

B) terminator

C) enhancer

D) activator

E) transcription factor

7) What is a trans-acting factor that increases transcription above the basal rate called?

A) repressor

B) activator

C) promoter

D) enhancer

E) basal factor

8) A putative regulatory sequence is fused to an enhancerless GFP gene in a reporter construct and that construct is then used to generate a transgenic organism. If the putative regulatory sequence contains an enhancer that binds with an eye-specific combination of activators, how will the transgenic organism look?

A) The entire body will glow green at all times.

B) Only the eyes will glow green at all times.

C) Only the eyes will glow green when exposed to a particular wavelength of light.

D) No parts of the transgenic organism will glow green.

9) Where do mutations that alter the amount of protein synthesized from a reporter construct occur most often?

A) the reporter gene

B) cis-acting DNA elements

C) X-gal coding sequence

D) RNA polymerase II gene

E) None of the choices is correct.

10) A trans-acting factor functions by

A) binding to enhancers or promoters leading to increased or decreased transcription.

B) regulating the expression of the gene from which it was transcribed.

C) transporting mRNAs from the nucleus to the cytoplasm.

D) binding to and increasing the activity of DNA polymerase.

E) binding only to promoters and increasing the binding of RNA polymerase.

11) Trans-acting proteins that influence transcription are generally referred to as

A) DNA polymerases.

B) tumor suppressors.

C) enhancers.

D) transcription factors.

E) promoters.

12) What do the promoters of nearly all eukaryotic genes contain?

A) a binding site for an activator

B) a TATA box

C) an ATG

D) a transcription start site

E) a binding site for a repressor

13) Which is true of enhancer DNA sequences? (Select all that apply.)

A) They contain TATA boxes.

B) They only function to increase gene transcription levels above the basal level.

C) They retain function if their nucleotide sequence is moved or inverted.

D) They can be more than 10 kilobases from the genes they regulate.

E) They may bind to more than one transcription factor at the same time.

14) What is a transcription factor that associates with an enhancer and causes an increase in initiation of transcription?

A) initiator

B) activator

C) repressor

D) enhancer

E) demethylase

15) What is the primary function of basal transcription factors?

A) repress transcription initiation of specific genes

B) assist RNA polymerase binding to the promoter

C) increase transcription by binding enhancer sequences

D) bind to activators or repressors and modify histone tails

E) add poly-A to the 3′ end of transcripts

16) Which is a type of DNA-binding domain found in transcription factors?

A) TAF

B) zinc finger

C) major groove

D) leucine zipper

E) corepressor

17) Two identical Jun polypeptides associate with each other via their leucine zippers to form an active transcription factor. What is the transcription factor called?

A) monomer

B) oligomer

C) heterodimer

D) homodimer

E) diplomer

18) The leucine zipper motif functions to

A) mediate the physical association of two polypeptides.

B) anchor transcriptional activator proteins to enhancer sequences.

C) release leucines from misfolded transcription factors.

D) integrate leucines and isoleucines into newly translated transcriptional activators.

E) separate DNA strands for transcription.

19) What is the term for transcription factors that decrease transcriptional activity?

A) deregulators

B) depleters

C) regulators

D) repressors

E) TBPs

20) What describes a situation in which an allele's expression depends on the parent from which it was inherited?

A) genomic imprinting

B) x chromosome inactivation

C) mosaicism

D) homodimerization

E) x-linkage

21) A variation in gene function that does not involve a change in DNA sequence but can be inherited is a(n)

A) enhancer trap.

B) replication origin.

C) Mendelian trait.

D) mutant chromosome.

E) epigenetic phenomenon.

22) In Drosophila females, Sxl protein directly alters the splicing pattern of the transcripts from which gene(s)? (Select all that apply.)

A) yp1

B) fru

C) Sxl

D) Tra

E) Dsx

23) The action of which small RNA inhibits the movement of transposable elements?

A) miRNA

B) siRNA

C) piRNA

D) tRNA

24) Recessive mutations in the Sxl gene in Drosophila are lethal in homozygous XX females because

A) without Sxl protein the expression of genes on both X chromosomes is increased.

B) increased Sxl protein signals male-specific development.

C) these mutations are the result of a loss of both X chromosomes.

D) Sxl is required for transcription of male-specific genes.

E) recessive mutations are always lethal in homozygotes.

25) Insulators act to

A) interfere with the association between enhancers and specific promoters.

B) remodel chromatin structure.

C) bind with repressors.

D) bind with activators.

26) Which is the best method to demonstrate the function of a putative enhancer?

A) Clone a region of DNA with the putative enhancer into a reporter construct, introduce the construct into eukaryotic cells, and measure expression of the reporter protein.

B) Compare DNA sequences from two or more species and identify conserved regions located outside of coding regions.

C) Introduce two separate pieces of DNA into a eukaryotic cell; one is a fragment of DNA with the putative enhancer and the other is a plasmid that contains a reporter gene.

D) Clone the putative enhancer into a reporter construct and measure the level of reporter gene expression in a prokaryotic cell.

E) Crosslink genomic DNA and associated proteins, fragment the DNA, use an antibody to isolate DNA sequences bound to a particular transcription factor, and sequence the DNA.

27) Enhancers can be identified by

A) cloning a region of DNA with the putative enhancer in a reporter plasmid and demonstrating an increase in gene expression when the construct is introduced into a eukaryotic cell.

B) sequence comparison with promoter sequences that are already known.

C) introducing two separate pieces of DNA into a eukaryotic cell.  One is a fragment of DNA with the putative enhancer and the other is a plasmid that contains a reporter gene. 

D) cloning the putative enhancer into a plasmid and measuring the level of reporter gene expression in a prokaryotic cell.

28) The ChIP technique can be used to identify putative DNA binding sites for various transcription factors because it

A) identifies DNA sequences bound to specific proteins.

B) identifies all sites bound by proteins in the nucleus.

C) identifies the size of different protein-DNA complexes.

D) identifies proteins that can interact with mRNA.

29) What is the relationship between methylation and genomic imprinting?

A) Differential methylation of DNA in males and females results in only one of the parental alleles being transcriptionally active in the offspring.

B) DNA methylation silences the alleles inherited from both parents, so no alleles are transcriptionally active.

C) Reversible methylation of DNA inherited from the father results in the paternal alleles being expressed only late in development.

D) Reversible methylation of DNA inherited from the mother results in the maternal alleles being expressed only late in development.

30) How can one primary mRNA result in several polypeptides with different amino acid sequences?

A) alternative splicing of exons

B) phosphorylation of proteins after translation

C) incorporation of an amino acid at a stop codon

D) addition of a poly-A tail to the mRNA

31) Why is the number of X chromosomes crucial for sex determination in Drosophila?

A) The Sxl promoter is responsive to the concentration of four transcription factors produced from genes on the X chromosomes.

B) The Sxl promoter is responsive to the concentration of four transcription factors produced from genes on the Y chromosome.

C) The X chromosome produces a single transcription factor that results in a male if at a low concentration and a female in a high concentration.

D) The Sxl promoter is repressed by increased concentrations of transcription factors that are produced from genes on the X chromosome.

32) Which statement is true about sex determination in Drosophila?

A) Alternative splicing of Sxl transcripts in females results in an active protein that directs alternative splicing of tra transcripts in females.

B) Sxl protein is produced early in males and it directs splicing of its own RNA to produce more Sxl in males.

C) Four autosomal genes produce transcription factors in males and the transcription factors activate male-specific gene expression.

D) Tra and Tra2 act together in males to alternatively splice dsx transcripts so that Dsx-M is produced.

Gene B is usually expressed only in skin cells. To learn about the mechanism by which expression of the gene B is regulated, you make clones that contain a GFP reporter and various parts of the upstream and downstream intergenic regions of genomic DNA that normally surround gene B (black lines) as shown in the figure below. The resulting clones were introduced into frog skin cells growing in the lab and levels of GFP expression was monitored by measuring green fluorescence. The table at left shows relative GFP expression, with more +s equal to more expression. (one + = basal expression).

33) Which area is likely to contain a cis-acting regulatory element? (Select all that apply.)

A) A

B) B

C) C

D) D

E) E

F) F

34) Which area contains the gene B promoter?

A) A

B) B

C) C

D) D

E) E

F) F

35) Which area contains an enhancer?

A) A

B) B

C) C

D) D

E) E

F) F

36) Which area is likely to bind to proteins that activate gene B (an activator)?

A) A

B) B

C) C

D) D

E) E

F) F

37) Interactions between an enhancer and a repressor initiates a series of events that result in a change in gene expression. In what order can the events occur? (Some steps may not be used. Put the remaining steps in chronological order from first to last.)

1. Transcription of the gene of interest is reduced.

2. A corepressor is recruited.

3. Chromatin around the gene of interest expands.

4. Histone tails may be methylated or deacetylated.

5. Chromatin around the gene of interest becomes more compact.

6. Proteins attached to the promoter and enhancer associate with each other and DNA bends.

A) 2, 4, 5, 1

B) 2, 6, 5, 1

C) 6, 4, 3, 1

D) 2, 6, 4, 5, 1

E) 4, 5, 1, 2

38) The enhancer shown in the diagram is able to regulate transcription of which genes?

(Select all that apply.)

A) Gene A

B) Gene B

C) Gene C

D) Gene D

39) This pedigree shows the segregation of a rare disease in a family. What is the most likely mode of inheritance of this disease? (assume complete penetrance)

Reference for pedigree: https://www.glowm.com/section_view/heading/Mendelian%20Inheritance%20and%20Its%20Exceptions/item/342

A) autosomal recessive

B) autosomal dominant

C) x-linked recessive

D) x-linked dominant

E) maternal inheritance

F) maternal imprinting

G) paternal imprinting

40) This pedigree shows the segregation of a rare disease in a family. What is the most likely mode of inheritance of this disease? (assume complete penetrance)

Reference for pedigree: http://cubocube.com/dashboard.php?a=1183&b=1269&c=103

A) autosomal recessive

B) autosomal dominant

C) x-linked recessive

D) x-linked dominant

E) maternal inheritance

F) maternal imprinting

G) paternal imprinting

41) This pedigree shows the inheritance pattern of a disease caused by a paternally imprinted allele in a family. Genetic testing of individuals I-1 and II-5 indicates they are carriers of the disease allele. No one else in the family agreed to be tested. If first cousins III-4 and III-5 have a child together (IV-1) what is the chance the child will have the disease? (assume complete penetrance)

Reference for pedigree: Modified from www.cell.com/trends/molecular-medicine/fulltext/S1471-4914(14)00138-5

A) 0

B) 1/9

C) 1/4

D) 1/2

E) 1/3

42) Which could be accomplished using ribosome profiling?

A) identifying enhancers that activate genes in muscle tissue

B) identifying all of the genes regulated by a particular transcription factor

C) quantifying the level at which the mRNAs in a cell are being translated

D) calculating the location and number of genes in a genome