Deck 12: Regulation of Gene Expression in Eukaryotes

Question 1

In addition to yeast cells,Gal4 has been shown to activate transcription in:

A)insect cells.
B)mouse cells.
C)human cells.
D)insect,mouse,and human cells.
E)None of the answer options are correct.

Answer 1

D

Question 2

The mating-type (MAT)locus in yeast has how many alleles?

A)1
B)2
C)3
D)4
E)The precise number is unknown.

Answer 2

B

Question 3

How many molecules of histones H2A,H2B,H3,and H4 (respectively)comprise a single nucleosome?

A)one each(i.e., 1, 1, 1, 1)
B)two each(i.e., 2, 2, 2, 2)
C)three each(i.e., 3, 3, 3, 3)
D)1,2,2,2
E)2,2,2,1

Answer 3

two each(i.e., 2, 2, 2, 2)

Question 4

The ________________ is a cis-acting element that binds trans-acting DNA-binding proteins.

A)promoter
B)enhancer
C)promoter-proximal element
D)GC-rich box
E)All of the answer options are correct.

Question 5

Analyzing mutations in the GAL80 and GAL3 indicate that:

A)both GAL80 and GAL3 inhibit GAL gene expression.
B)both GAL80 and GAL3 promote GAL gene expression.
C)GAL80 promotes GAL gene expression,and GAL3 inhibits GAL gene expression.
D)GAL80 inhibits GAL gene expression,and GAL3 promotes GAL gene expression.
E)GAL80 and GAL3 are not involved in GAL expression.

Question 6

In eukaryotes,transcriptional gene control is mediated by:

A)trans-acting factors binding to cis-acting elements.
B)trans-acting factors failing to bind to cis-acting elements.
C)repressor proteins binding to operator sites.
D)metabolites binding to cis-acting elements.
E)None of the answer options are correct.

Question 7

The "domain-swapping" experiment that grafts the Gal4 activation domain to the LexA DNA-binding domain generates a chimeric protein that will:

A)bind to the Gal4 site.
B)bind to the LexA site.
C)activate transcription of the Gal4 gene.
D)activate transcription of the Gal7 gene.
E)All of the answer options are correct.

Question 8

In yeast,which of these is NOT a function of MAT genes?

A)controlling the expression of structural genes in a and α cells
B)MATa locus encoding a regulatory protein (a1)that affects only diploid cells
C)MATa locus encoding a regulatory protein (a1)that affects both haploid and diploid cells.
D)MATα allele encoding a regulatory protein (α2)that represses expression of a specific genes
E)None of the answer options are correct.

Question 9

Which of the following GAL genes are located on the same chromosome?

A)GAL1 and GAL2
B)GAL1 and GAL10
C)GAL2 and GAL10
D)GAL2 and GAL7
E)All of the answer options are correct.

Question 10

In eukaryotes,primary mRNA transcripts are extensively processed,which include(s):

A)modification of the 5′ end.
B)modification of the 3′ end.
C)removal of introns by splicing.
D)None of the answer options are correct.
E)modification of either end and removal of introns by splicing.

Question 11

The ________________ is a cis-acting element that binds regulatory proteins.

A)promoter
B)operator
C)promoter-proximal element
D)TATA box
E)All of the answer options are correct.

Question 12

GAL3 promotes GAL gene expression by:

A)binding galactose only and subsequently binding to Gal80.
B)binding ATP only,and subsequently binding to Gal80.
C)binding galactose and ATP,and subsequently binding to Gal80.
D)binding galactose and ATP,and subsequently binding to Gal1,Gal7,and Gal10.
E)binding to the Gal upstream activation sequence (UAS).

Question 13

In the bacterial lac operon,the physiologically regulated step is:

A)DNA-binding by the transcriptional regulator.
B)activity of the activation-domain of the transcriptional regulator.
C)feedback inhibition by the end-product of the pathway.
D)import of the inducer molecule.
E)None of the answer options are correct.

Question 14

The GAL4 enhancers are located _____ of the genes they regulate and are known as ______.

A)downstream;downstream activation sequences (DAS)
B)downstream;downstream enhancer sequences (DES)
C)upstream;upstream activation sequences (UAS)
D)upstream;upstream enhancer elements (UES)
E)None of the answer options are correct.

Question 15

The ________________ is a cis-acting element that binds RNA polymerase II.

A)promoter
B)enhancer
C)promoter-proximal element
D)GC-rich box
E)All of the answer options are correct.

Question 16

Eukaryotic and bacterial RNA polymerases are different such that:

A)eukaryotes have several types of RNA polymerases,whereas bacteria only have one.
B)unlike bacterial RNA polymerase,eukaryotic RNA pol II can synthesize mRNA and also coordinate mRNA processing.
C)eukaryotic RNA polymerases are multimeric,whereas bacterial RNA polymerase is not.
D)eukaryotes have several types of RNA polymerases,one of which can synthesize mRNA and also coordinate mRNA processing,whereas bacteria only have one type of RNA polymerase that does not coordinate mRNA processing.
E)eukaryotes have several types of multimeric RNA polymerases,whereas bacteria only have one monomeric RNA polymerase.

Question 17

In the presence of the sugar galactose,the expression levels of GAL1,GAL2,GAL7,and GAL10 are ______________ as compared to the absence of galactose.

A)1000-fold higher
B)1000-fold lower
C)10-fold higher
D)10-fold lower
E)the same

Question 18

In the eukaryotic GAL system,the physiologically regulated step is

A)DNA-binding by the transcriptional regulator.
B)activity of the activation-domain of the transcriptional regulator.
C)feedback inhibition by the end-product of the pathway.
D)import of the inducer molecule.
E)None of the answer options are correct.

Question 19

The GAL4 protein has which of the following functional domains?

A)a DNA-binding domain
B)an activation domain
C)a repressor domain
D)a DNA-binding domain and an activation domain
E)a DNA-binding domain and a repressor domain

Question 20

GAL80 inhibits GAL gene expression by:

A)specifically binding to Gal4 and preventing DNA-binding.
B)specifically binding to Gal4 and preventing activation.
C)specifically binding to Gal3 and preventing DNA-binding.
D)specifically binding to Gal3 and preventing activation.
E)inducing an allosteric change in Gal3.

Question 21

Which of the following describes the histones associated with the nucleosomes of active genes?

A)poor in acetyl groups (i.e. ,hypoacetylated)
B)rich in acetyl groups (i.e. ,hyperacetylated)
C)rich in phosphate groups (i.e. ,hyperphosphorylated)
D)poor in phosphate groups (i.e. ,hypophosphorylated)
E)None of the answer options are correct.

Question 22

Regions of a chromosome that are bundled in highly condensed chromatin are known as:

A)homochromatin.
B)heterochromatin.
C)euchromatin.
D)epichromatin.
E)hyperchromatin

Question 23

A Barr body refers to:

A)a sex-linked trait in cats.
B)a recessive trait in fruit flies.
C)an inactivated Y chromosome.
D)spore formation in Neurospora.
E)None of the answer options are correct.

Question 24

Which histone is considered the "linker" that compacts nucleosomes into higher order structures?

A)H1
B)H2A
C)H2B
D)H3
E)H4

Question 25

Which of the following describes the histones associated with the nucleosomes of inactive genes?

A)poor in acetyl groups (i.e. ,hypoacetylated)
B)rich in acetyl groups (i.e. ,hyperacetylated)
C)rich in phosphate groups (i.e. ,hyperphosphorylated)
D)poor in phosphate groups (i.e. ,hypophosphorylated)
E)None of the answer options are correct.

Question 26

The regulatory element that evolved to prevent enhancers from promiscuously activating promoters is known as:

A)the first stage of mitosis.
B)the changing of amino acid position.
C)enhancer-blocking elements.
D)the changing of nucleotide position.
E)None of the answer options are correct.

Question 27

The enzyme responsible for adding methyl groups to histone proteins is called:

A)histone acetylase (HA).
B)histone deacetylase (HDAC).
C)histone acetylmethyltransferase (HAT).
D)histone acetyltransferase (HAT).
E)histone methyltransferase (HMT).

Question 28

The enzyme responsible for removing acetyl groups from histone proteins is called:

A)histone acetylase (HA).
B)histone deacetylase (HDAC).
C)histone acetylmethyltransferase (HAT).
D)histone acetyltransferase (HAT).
E)histone methyltransferase (HMT).

Question 29

DNA elements that prevent the spreading of heterochromatin into adjacent euchromatic regions are called:

A)enhancer blocking elements.
B)euchromatin buffers.
C)barrier insulators.
D)barrier buffers.
E)barrier-blocking elements.

Question 30

In mice,the H19 allele is only expressed if it is:

A)inherited from the mother.
B)inherited from the father.
C)mutated in the mother.
D)mutated in the father.
E)None of the answer options are correct.

Question 31

What is chromatin remodeling?

A)the first stage of mitosis
B)the changing of amino acid position
C)the changing of nucleosome position
D)the changing of nucleotide position
E)None of the answer options are correct.

Question 32

The phenomenon in D.melanogaster known as Position-Effect Variegation (PEV)provides powerful evidence that:

A)DNA is the genetic material.
B)posttranscriptional mechanisms regulate gene expression.
C)transcriptional mechanisms regulate gene control.
D)chromatin structure is unable to regulate gene expression.
E)chromatin structure is able to regulate gene expression.

Question 33

Compared to heterochromatin,euchromatin is:

A)rich in genes and comprised of densely packed nucleosomes.
B)poor in genes and comprised of densely packed nucleosomes.
C)rich in genes and comprised of loosely packed nucleosomes.
D)poor in genes and comprised of loosely packed nucleosomes.
E)rich in genes and completely lacking nucleosomes.

Question 34

In mice,the igf2 allele is only expressed if it is:

A)inherited from the mother.
B)inherited from the father.
C)mutated in the mother.
D)mutated in the father.
E)None of the answer options are correct.

Question 35

What portion of a histone is typically modified by acetylation/de-acetylation?

A)acidic amino acid residues in the "head" region of the histone
B)basic amino acid residues in the "head" region of the histone
C)basic amino acid residues in the "tail" region of the histone
D)acidic amino acid residues in the "head" region and basic amino acid residues in the "tail" region
E)None of the answer options are correct.

Question 36

The enzyme responsible for adding acetyl groups to histone proteins is called:

A)histone acetylase (HA).
B)histone deacetylase (HDAC).
C)histone acetylmethyltransferase (HAT).
D)histone acetyltransferase (HAT).
E)histone methyltransferase (HMT).

Question 37

Regions of a chromosome that are packaged in less-condensed chromatin are known as:

A)homochromatin.
B)heterochromatin.
C)euchromatin.
D)epichromatin.
E)hyperchromatin.

Question 38

What is an enhanceosome?

A)a large complex that acts synergistically to activate translation
B)a large complex that acts synergistically to activate transcription
C)an aggregation of nucleosomes that activates transcription
D)an aggregation of nucleosomes that activates translation
E)a large complex that promotes epigenetic inheritance

Question 39

Methylation of H3 lysine residue 4:

A)is associated with activation of gene expression.
B)is associated with repression of gene expression.
C)has no effect on gene expression.
D)creates binding sites for other gene repressors.
E)None of the answer options are correct.

Question 40

Epigenetic inheritance is defined as the inheritance of:

A)nuclear DNA from one cell generation to the next.
B)extra-chromosomal DNA from one cell generation to the next.
C)mRNA from one cell generation to the next.
D)chromatin states from one cell generation to the next.
E)None of the answer options are correct.

Question 41

Genomic imprinting in mice is mediated by the imprinting control region (ICR).In the paternal allele the:

A)enhancer element is methylated and serves as a buffer-insulator.
B)ICR is methylated,which allows H19 transcription.
C)ICR is not methylated,which allows H19 transcription.
D)ICR is not methylated,which allows Igf2 transcription.
E)ICR is methylated,which allows Igf2 transcription.

Question 42

The miRNA-RISC complex is known to inhibit translation.List several possible mechanisms for translational inhibition mediated by miRNA-RISC.

Question 43

Expression of a gene in a mammal can sometimes be associated with the parent from which the gene was inherited (mother or father).What term is used to describe the situation where an allele that is inherited from the father is expressed,but the homologous allele inherited from the mother is not?

A)paternal imprinting
B)maternal imprinting
C)autosomal imprinting
D)Y-linked inheritance
E)X-linked inheritance

Question 44

Histones are essentially identical in sequence/structure in all eukaryotic organisms from yeast to plants to animals.What does this say about the biophysical properties of DNA-packaging and the evolution of eukaryotic organisms?

Question 45

Describe the difference between transcriptional gene regulation and post-transcriptional gene regulation in eukaryotes.

Question 46

Genomic imprinting in mice is mediated by the imprinting control region (ICR).In the maternal allele the:

A)enhancer element is methylated and serves as a buffer-insulator.
B)ICR is methylated,which allows H19 transcription.
C)ICR is not methylated,which allows H19 transcription.
D)ICR is not methylated,which allows Igf2 transcription.
E)ICR is methylated,which allows Igf2 transcription.