Deck 13: Chromatin Structure and Its Effect on Transcription

Question 1

One method used by researchers to demonstrate the existence of nucleosome free DNA regions is

A)RNA Polymerase Run-off experiments.
B)Nuclear Run on experiments.
C)Reporter gene experiments.
D)Anion Exchange chromatography.
E)DNase hypersensitivity experiments.

Answer 1

E

Question 2

Histones have been shown to have an up regulatory effect on gene activity in vitro.

Answer 2

False

Question 3

Human DNA is folded into ________ that consist of core histones wrapped by DNA.

Answer 3

nucleosomes

Question 4

Which of the following is the most common type of histone modification?

A)lysine $\varepsilon$ -amino methylation
B)serine o-phosphorylation
C)lysine n-phosphorylation
D)histidine n-phosphorylation
E)acetylation

Question 5

Most eukaryotic cells contain four different kinds of histone proteins.

Question 6

Deacetylation of core histones allows for stronger binding of histones to DNA,which then inhibits ___________________.

Question 7

Which of the following is the correct order of chromatin folding?

A)nucleosome formation,30 nM fiber formation,radial loop structure
B)radial loop structure,30 nM fiber formation,nucleosome formation
C)30 nM fiber formation,nucleosome formation,radial loop formation
D)30 nM fiber formation,radial loop formation,nucleosome formation
E)nucleosome formation,radial loop formation,nucleosome formation

Question 8

The histone protein _______ is more readily removed from chromatin than the other histone proteins and therefore is not considered part of the core nucleosome.

Question 9

Chromatin remodeling usually occurs on euchromatin,while heterochromatin is very condensed and genetically inactive.

Question 10

Which of the following histone proteins is the most highly conserved from one organism to another?

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

Question 11

Unacetylated histones tend to ______________ transcription.

Question 12

Which of the following molecules can expedite RNA Pol II elongation through a nucleosome?

A)HAT
B)FACT
C)IFN- $\beta$
D)ChIP
E)TRE

Question 13

Antirepressors such as GAGA factor are thought to compete with ________ for binding sites on the DNA template.

Question 14

Some transcription factors,such as ________ can act as both antirepressors and transcription activators.

A)GAL4
B)Rad6
C)SIR2
D)RAP1
E)HP1

Question 15

At least 20% of all amino acids found in histones are the basic amino acids

A)glycine or serine.
B)arginine or lysine.
C)tryptophane or tyrosine.
D)valine or praline.
E)cysteine or isoleucine.

Question 16

On average,there is one nucleosme per _______bp of DNA.

Question 17

The Histone Code states that the

A)primary sequence of the histone proteins never changes over time.
B)combination of histone modification on a given nucleosome near a gene's control region affects the efficiency of transcription of that gene.
C)combination of histone modification on a given nucleosome near a gene's control region affects the efficiency of transcription of all the nearby genes.
D)lysines are the only amino acids found in histones that can be acetylated and deacetylated.
E)histones are found in all living cells.

Question 18

Histone acetylation can occur in the

A)nucleus.
B)cytoplasm.
C)ER lumen.
D)nucleus and cytoplasm.
E)nucleus,cytoplasm,and ER lumen.

Question 19

Acetylation of histones occurs on the amino groups of the side chains of the amino acid __________.

Question 20

Histone acetyltransferase transfers acetyl groups from _______ to core histones.

Question 21

Layborne and Kadonage demonstrated in vitro that by adding increasing amounts of core histones and H1 they could repress transcription from the Drosophila Krüppel gene.

Question 22

Nucleosome remodeling can either activate or repress transcription.

Question 23

Chromatin immunoprecipitation (ChIP)can be used to study chromatin methylation in yeast cells.

Question 24

In nucleosome positioning,activators force the nucleosome to take up positions around the promoter so RNA polymerase can bind.

Question 25

The energy necessary for chromatin remodeling comes from ATP.

Question 26

If histone acetylation occurs in the cytoplasm,then histone deacetylation will also occur in the cytoplasm.

Question 27

Transcription factors help stabilize nucleosomes.

Question 28

Histone acetylation usually promotes gene activity.

Question 29

When added to DNA in vitro,unacetylated histones tend to increase transcription from the 5S rRNA promoter.