Download doc Quiz #1

1.
2009 Quiz 1--Question 1
Which of the following statements about amino acids is false?
1.
2.
3.
4.
5.
Score:
Student
Value
Response
Asparagine 100%
is an acidic
amino acid.
Lysine and
histidine are
both basic
amino acids,
and lysine is
more
strongly
basic than
histidine.
Leucine,
valine, and
alanine are
all
hydrophobic
amino acids.
Peptide
bonds
involving
proline
place local
limitations
on the
ability of a
protein to
fold.
Tryptophan
has a large,
bulky side
chain.
Correct Answer
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2.
2009 Quiz 1--Question 2
Inosine is a purine that is identical to adenine, except that the amine group attached to carbon 6 is
replaced with a keto group. If inosine were incorporated into double stranded DNA, how many hydrogen
bonds could it form with cytosine and how many with thymine? How many repulsive ionic interactions
would occur between inosine and cytosine, and how many would occur between inosine and thymine?
1.
2.
3.
4.
5.
Student
Value Correct Answer
Response
hydrogen
They messed up
bonds: 1
this question so
with
they put all
thymine, 3
answers as right.
with
cytosine
repulsive
interactions:
1 with
thymine, 0
with
cytosine
hydrogen
bonds: 2
with
thymine, 3
with
cytosine
repulsive
interactions:
0 with
thymine, 1
with
cytosine
hydrogen 0%
bonds: 1
with
thymine, 2
with
cytosine
repulsive
interactions:
1 with
thymine, 1
with
cytosine
hydrogen
bonds: 0
with
thymine, 3
with
cytosine
repulsive
interactions:
0 with
thymine, 0
with
cytosine
hydrogen
bonds: 3
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with
thymine, 3
with
cytosine
repulsive
interactions:
0 with
thymine, 0
with
cytosine
Score:
0/0.2
3.
2009 Quiz 1--Question 4
Which of the following factors is responsible for a water molecule being a dipole?
1.
2.
3.
4.
5.
Score:
Student
Value Correct Answer
Response
the similarity in
electronegativity
of hydrogen and
oxygen
the tetrahedral
structure of
liquid water
the magnitude 100%
of the H–O–H
bond angle
the ability of
water to
hydrogen bond
to various
chemical
structures
the difference in
bond strength
between
hydrogen bonds
and covalent
bonds
0.2/0.2
4.
2009 Quiz 1--Question 5
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All of the following are correct about a primary transcript in eukaryotes except that it
(Note: the 'functional RNA' is the mRNA or the noncoding RNA that results after processing of the
primary transcript.)
1.
2.
3.
4.
5.
Score:
Student
Value
Response
is usually
longer than
the
functional
RNA.
may
contain
nucleotide
sequences
that are not
present in
the
functional
RNA.
contains no
modified
bases.
could
contain
information
for more
than one
RNA
molecule.
contains a 100%
TATA box.
Correct Answer
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5.
Question 8
What happens to a supercoiled, circular DNA molecule if it becomes nicked?
Student
Value
Response
1. Torsional
stress
increases and
a linear
molecule
forms.
Correct Answer
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2. Torsional
stress
decreases
and a linear
molecule
forms.
Torsional
100%
3. stress
decreases
and a relaxed
circle forms.
4. Torsional
stress
increases and
a relaxed
circle forms.
5. Transcription
is initiated.
Score:
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6.
1. Alternative splicing
Assuming that all three exons can be alternatively spliced, how many distinct mRNAs can be generated
from the gene below?
Student
Value
Response
1. 3
2. 6
7
100%
3.
4. 24
5. 72
Score:
Correct Answer
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7.
Question 1-4
Which of these fragments of DNA has the highest melting temperature?
Both complementary strands for each fragment are shown (names 1st and 2nd)
Student Response
Value
Correct
Answer
Feedback
1. 1st TATATAAATTTATTTAA
2nd
_____ATATATTTAAATAAATT
2. 1st ACAAATGTCTGCGATT
2nd
_____TGTTTACAGACGCTAA
3. 1st AGACAAGTCC
2nd _____TCTGTTCAGG
1st AGACAAGTCCGCGATT
100%
4. 2nd
_____TCTGTTCAGGCGCTAA
Score:
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8.
Question 1-5
Which statement(s) is/are true?
1.
2.
3.
4.
5.
Student
Value
Response
Ions can cross
lipid bilayers
only if they
are smaller
than a water
molecule
Biomembranes
are composed
of
hydrophobic
molecules
Phospholipids 100%
can diffuse
rapidly within
the plane of
the membrane
The amino
acid leucine in
its monomeric
form can cross
freely lipid
bilayers
Phospholipids
interact with
other
phospholipids
Correct Answer
Feedback
through ionic
interactions
Score:
0.2/0.2
9.
Question 1-9
Which statement(s) is/are true?
1.
2.
3.
4.
Score:
Student
Value
Response
Hydrogen 50%
bonds can
be
disrupted
by heat
Hydrogen 50%
bonds can
be formed
between
methanol
and water
Hydrogen
bonds can
be formed
between a
CH3group and
a NH2group.
Hydrogen
bonds are
weaker
than van
der Waals
interactions
Correct Answer
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10.
RNA processing
Referring to the diagram below, which of the following are true of the mature RNA transcript encoded by
this gene? More than one answer may be correct, so you may select multiple responses. You will lose
partial credit for each incorrect response selected, and gain partial credit for each correct response
selected.
1.
2.
3.
4.
5.
Student
Value
Response
All
nucleotides
in the
primary
transcript are
found in the
mature
transcript.
All
nucleotides
in the mature
transcript are
found in the
primary
transcript.
Transcription 100%
begins at the
+1 position.
Translation
begins at the
+1 position.
None of the
above are
true.
Correct Answer
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