Download Exam 2 Practice #4

Practice Exam III
1.
In prokaryotes, chromatin packing is a broad means of regulating gene expression.
A.
True
B.
False
2.
Forming chromatin fibers (euchromatin) from nucleosomes requires the presence of
A.
Protein scaffold
B.
Non-histone proteins
C.
H1 histone proteins
D.
Heterochromatin
3.
A region of DNA is not being transcribed. Which of the following likely describes its
condition?
A.
The histone tails have multiple methyl groups attached
B.
The histone tails have multiple acetyl groups attached
C.
Nucleosomes are not present
D.
DNA is condensed into heterochromatin
E.
A&D
F.
B&C
4.
At the enhancer region of eukaryotic genes, __________ transcription factors bind
while at the promoter region _________________ transcription factors bind.
A.
General, specific
B.
Specific, general
C.
Functional, non-functional
D.
Non-functional, functional
5.
Regulation of gene expression primarily occurs at which stage in eukaryotes?
A.
Transcription
B.
Post-transcription modification of mRNA
C.
Translation
D.
Post-translation modification of polypeptides
E.
None of the above
6.
If a region of eukaryotic DNA is actively being transcribed, which of the following
most likely describes it?
A.
DNA arranged in looped domains
B.
Heterochromatin present
C.
Histone tails are methylated
D.
Histone tails are acetylated
E.
A&D
7.
All somatic (body) cells of a multicellular organism contain identical genetic
information.
A.
True
B.
False
8.
Cell differentiation is characterized by
A.
Every individual cell containing a set of genes unique to itself
B.
Each cell type expressing a unique combination of genes
C.
Each cell type transcribing certain regions of its genome but not others
D.
B&C
E.
All of the above
9.
In eukaryotic genome organization, an enhancer is
A.
A binding site for specific transcription factors found far from the promoter
B.
A binding site for general transcription factors found within the promoter
C.
A binding site for specific transcription factors found within the promoter
D.
A binding site for general transcription factors found far from the promoter
10.
There are many more genes in the human genome than there are specific
transcription factors. This is possible because
A.
gene expression is regulated by a specific combination of enhancers
B.
gene expression is regulated by a combination of specific and general
transcription factors
C.
of combinatorial regulation
D.
A&C
E.
B&C
11.
Shortening of the 3’ polyA tail of a piece of mRNA will lead to
A.
Removal of the 5’ cap
B.
Blocking of translation by miRNA and siRNA
C.
Lower stability in the cytoplasm
D.
None of the above
Questions 12-16 Arrange the statements found in the right hand column in chronological
order as they happen in eukaryotic gene expression (first event would be for 12 second 13…)
12.
13.
14.
15.
16.
C
E
B
D
A
A.
B.
C.
D.
E.
binding of large ribosomal subunit to mRNA
binding of small ribosomal subunit to mRNA
post-transcription modification of pre-mRNA
binding of aminoacyl-tRNA with methionine
movement of mRNA from nucleus to cytoplasm
17.
T or F There is only one type of aminoacyl-tRNA synthetase.
A.
True
B.
False
18.
Wobble would allow _____________ to occur during translation.
A.
T to pair with G
B.
U to pair with G
C.
A to pair with C
D.
B&C
E.
All of the above
19.
Multiple polypeptides can arise from the same gene due to
A.
alternative RNA splicing
B.
polyribosomes
C.
reverse transcriptase
D.
All of the above
20.
Which enzyme allows DNA polymerase III to begin synthesis of the daughter strand
of DNA?
A.
DNA polymerase III can bind directly to the existing template strand without
assistance
B.
DNA polymerase I
C.
Primase
D.
Ligase
E.
None of the above
Questions 21-24 Match the following enzymes with their function.
21.
22.
23.
24.
Joins Okazaki fragments E
stabilizes each template DNA strand during replication C
Prevents stressed DNA helix from breaking D
Creates replication bubble by unwinding DNA helix A
A. Helicase
B. Bubblease
C. Single Strand Binding Proteins
D. Topoisomerase
E. Ligase
25.
Telomeres prevent loss of information at the _____end of _______ DNA strands.
A.
3’ , daughter
B.
5’ , daughter
C.
3’ , template
D.
5’ , template
26.
If one or two nucleotides are deleted from an mRNA molecule, but not three, a _______ will
occur.
A.
missense
B.
nonsense
C.
frame shift
D.
point mutation
27.
Retroviruses form a ______ within their host cells’ DNA.
A.
Provirus
B.
Prophage
C.
Glycoprotein
28.
A.
B.
C.
D.
E.
is a prokaryote acquiring DNA from its environment.
Transcription
Transduction
Transformation
Conjugation
None of the above
29.
When bacterial genetic material is transferred from one host to a subsequent host via imprecise
excision of a phage,
has occurred.
A.
Transcription
B.
Transduction
C.
Transformation
D.
Conjugation
E.
None of the above
30.
When tryptophan is present in high concentration in E. coli, the trp operon will be
A.
induced
B.
repressed
C.
transcribed
D.
translated
E.
mutated