|
The table below summarizes data obtained in an experiment on oxygen evolution by different plants species grown under different lighting conditions. Assume that the plants are of comparable size.
Plant
|
Type of light
|
Volume of oxygen given off (mL)
|
Temperature (C)
|
Time (days)
|
Corn
|
incandescent
|
200
|
20
|
5
|
Corn
|
fluorescent
|
400
|
22
|
10
|
Barley
|
incandescent
|
200
|
22
|
5
|
Barley
|
fluorescent
|
150
|
22
|
5
|
____ 68. Which of the following is a reasonable interpretation?
a.
|
oxygen production is more rapid in barley in incandescent light than fluorescent light
|
b.
|
less oxygen is evolved per day in incandescent light than in fluorescent light
|
c.
|
in incandescent light, both corn and barley give off he same amount of oxygen
|
d.
|
at 22°C, corn gives off more oxygen than oats
|
e.
|
in incandescent light, corn gives off more oxygen per day than does oats
|
Imagine you have five small glass jars that are sealed to the atmosphere. All the jars are filled with a bicarbonate solution (as a source of carbon dioxide) and an indicator. The differences between each jar are described below:
Jar #1: Has a small fish.
Jar #2: Has one small fish in addition to some aquatic plants.
Jar #3: Has three small fish in addition to some aquatic plants.
Jar #4: Has some aquatic plants.
Jar #5: Has some aquatic plants, but the jar is completely surrounded by aluminum foil.
The indicator shows you how much carbon dioxide is in each jar. The following table shows the relative amounts:
Colour of pH indicator solution
|
Relative amount of carbon dioxide
|
red
|
high
|
green
|
medium (equivalent to atmosphere)
|
blue
|
low
|
The following table shows the results of an experiment where the tubes were allowed to stand under natural light for several hours.
Observation
|
Jar #1
|
Jar #2
|
Jar #3
|
Jar #4
|
Jar #5
|
Starting colour of indicator
|
green
|
green
|
green
|
green
|
green
|
Final colour of indicator
|
red
|
green
|
red
|
blue
|
green
|
____ 69. Under what circumstance would the indicator change from red to green in Jar#3?
a.
|
removing some of the aquatic plants
|
b.
|
illuminating the jar with green light
|
c.
|
adding some aquatic plants to the jar
|
d.
|
adding some fish to the jar
|
e.
|
covering the jar with tin foil
|
____ 70. During DNA replication, the function of RNA primers is to
a.
|
open replication bubbles
|
b.
|
serve as starting points for DNA strand elongation by DNA polymerase I in the 3' - 5' direction
|
c.
|
serve as starting points for DNA strand elongation by DNA polymerase III in prokaryotes
|
d.
|
prevent new-separated strands of DNA from rejoining
|
e.
|
serve as a binding site for DNA ligase
|
____ 71. If a free phosphate is found at the 5' end of a DNA strand, what is found at the other end of the same strand?
a.
|
a hydroxyl group on the 5' carbon of a deoxyribose sugar
|
b.
|
a hydroxyl group on the 3' carbon of a deoxyribose sugar
|
c.
|
a phosphate group on the 5' carbon of a deoxyribose sugar
|
d.
|
a phosphate group on the 3' carbon of a deoxyribose sugar
|
e.
|
a base attached to the 3' carbon of a deoxyribose sugar
|
____ 72. In their experiment that showed that DNA replication in E. coli was semi-conservative, Meselson and Stahl used
a.
|
a radioactive isotope of nitrogen
|
b.
|
nitrogen isotopes having different mass
|
c.
|
ultraviolet light
|
d.
|
radioactive phosphorus
|
e.
|
nitrogen isotopes which had different numbers of protons
|
____ 73. In DNA, phosphodiester bonds join
a.
|
two phosphate groups
|
d.
|
phosphate groups and bases
|
b.
|
bases and sugars
|
e.
|
two sugar molecules
|
c.
|
phosphate groups and sugars
|
|
____ 74. A section of mRNA 9 codons long would most likely result in the addition of how many amino acids to a growing polypeptide (the stop codon is absent from the section of mRNA)?
a.
|
9
|
d.
|
27
|
b.
|
5
|
e.
|
3
|
c.
|
10
|
|
____ 75. The temperatures at which two segments of DNA unwind has been established. Segment A unwinds at 71.6 C, while segment B unwinds at 80.7 C. The difference is due to the fact that
a.
|
A is more phosphorylated than B
|
b.
|
B is richer in adenine-thymine pairs than A
|
c.
|
B is richer in adenine-uracil pairs than A
|
d.
|
B is richer in cytosine-guanine pairs than A
|
e.
|
A is richer in adenine-cytosine pairings than B
|
____ 76. If transcription could proceed in both directions along both DNA strands of a gene, how many different polypeptides could be coded for by a single gene?
a.
|
1
|
d.
|
4
|
b.
|
2
|
e.
|
none
|
c.
|
3
|
|
____ 77. There are differences in the amino acid sequence of rabbit and frog haemoglobin polypeptides. If mRNA for rabbit haemoglobin is extracted from rabbit red blood cells, and is then placed in frog eggs, the cells will produce rabbit haemoglobin polypeptides. This shows that
a.
|
rabbit haemoglobin mRNA is the same as frog haemoglobin mRNA
|
b.
|
the genetic code and the machinery of translation are substantially the same in widely-different organisms
|
c.
|
the gene for haemoglobin is identical in all organisms
|
d.
|
the DNA for rabbit hemoglobin is reverse transcribed into DNA in the frog eggs
|
e.
|
frog ribosomes are incapable of binding to mammalian RNA
|
____ 78. The repressor protein of the lac operon has two different recognition and binding sites for other molecules. Which of the following pairs of molecules do you think it likely that these sites would bind?
a.
|
RNA polymerase and lactose
|
b.
|
RNA polymerase and DNA
|
c.
|
a DNA sequence on the operator and lactose
|
d.
|
a DNA sequence on the regulator gene and lactose
|
e.
|
lactose and DNA polymerase
|
____ 79. If you were shown an electron micrograph of a cell in which mRNA was being translated while it was still being transcribed from the DNA, you would know
a.
|
the gene product was in high demand at the point in the cell cycle at which the image was captured
|
b.
|
the cell was prokaryotic
|
c.
|
transcription was occurring extremely fast
|
d.
|
the electron micrograph showed the nucleus of the cell
|
e.
|
the cell was eukaryotic
|
____ 80. It is thought possible that the evolution of modern eukaryotic cells involved an endosymbiotic relationship between the prokaryotic cell ancestral to mitochondria and a host prokaryotic cell. Which of the following is not true?
a.
|
Mitochondria have DNA organized into a few tiny chromosomes held in a mini-nucleus.
|
b.
|
The sequence of the DNA of mitochondria is similar to that of bacterial DNA.
|
c.
|
Mitochondria divide by fission.
|
d.
|
The prokaryotes ancestral to mitochondria may have had compartmentalized organelles.
|
e.
|
Mitochondria have replication, transcription, and translation systems distinct from those of the host cell.
|
____ 81. Which of the following is not an example of noncoding DNA?
a.
|
VNTRs
|
d.
|
SINES
|
b.
|
telomeres
|
e.
|
histones
|
c.
|
LINES
|
|
____ 82. Compare the two mRNA sequences below.
AUAUUCGGCAAUCCG
AUAUUCCGCAAUCCG
This change could be the result of a
a.
|
nonsense mutation
|
d.
|
translocation
|
b.
|
addition mutation
|
e.
|
point mutation
|
c.
|
deletion mutation
|
|
____ 83. Mutations can be inheritable if they effect cells in the
a.
|
placenta
|
d.
|
testes
|
b.
|
fallopian tubes
|
e.
|
skin
|
c.
|
prostate
|
|
____ 84. There are three kinds of RNA polymerase in eukaryotes—RNA polymerases I, II, and III. RNA polymerases I, II, and III are used, respectively, to transcribe
a.
|
mRNA, tRNA, rRNA
|
d.
|
tRNA, rRNA, mRNA
|
b.
|
tRNA, mRNA, rRNA
|
e.
|
all transcribe mRNA
|
c.
|
rRNA, mRNA, tRNA
|
|
____ 85. In a eukaryotic cell, the sizes of the large and small ribosome subunits are, respectively
a.
|
50S, 40S
|
d.
|
80S, 60S
|
b.
|
60S, 50S
|
e.
|
80S, 70S
|
c.
|
60S, 40S
|
|
____ 86. The following are all steps in the production of a bacterium having recombinant DNA, which includes an inserted nonbacterial gene. They are in random order.
1. gel electrophoresis of plasmid DNA from bacteria in colonies showing antibiotic resistance
|
2. sticky ends are allowed to pair up
|
3. a restriction endonuclease is used to remove the gene to be inserted from its source and also to cut open a plasmid that includes a gene for antibiotic resistance
|
4. the bacterial colonies are treated with antibiotic
|
5. treatment with ligase
|
6. transformation
|
The correct order of these steps is
a.
|
2,5,1,3,4,6
|
d.
|
3,2,5,6,4,1
|
b.
|
4,3,6,2,5,1
|
e.
|
6,3,5,2,4,1
|
c.
|
5,1,2,3,4,6
|
|
____ 87. Gel electrophoresis separates fragments of DNA using
a.
|
a sieving medium through which DNA fragments are moved by gravitational forces
|
b.
|
repulsion of charged DNA molecules by the electrically charged gel beads
|
c.
|
a sieving medium through which DNA molecules are moved by electrical forces
|
d.
|
movement through a sieving medium by positively charged DNA molecules attracted by a negative pole
|
e.
|
movement of DNA fragments of different sizes at different speeds as a result of ultracentrifugation
|
____ 88. The recognition sites of five restriction endonucleases are shown below. Which would make cuts in the following DNA fragment? You will need to draw in the complementary DNA strand before attempting this question.
5'-GCAAGCTTGCTGCAGAATTACCCGGA-3'
|
|
Recognition Sites:
|
|
|
EcoRI
|
5'-GAATTC-3'
3'-CTTAAG-5'
|
|
|
SmaI
|
5'-GGGCCC-3'
3'-CCCGGG-5'
|
|
|
AluI
|
5'-AGCT-3'
3'-TCGA-5'
|
|
|
HindIII
|
5'-AAGCTT-3'
3'-TTCGAA-5'
|
a.
|
HindIII and SmaI
|
d.
|
EcoRI and HindIII
|
b.
|
EcoRI and AluI
|
e.
|
AluI and HindIII
|
c.
|
EcoRI and SalI
|
|
____ 89. Restriction endonuclease digestion of a DNA sequence yielded fragments of the following sizes:
1. 5.2 kb
2. 0.8 kb
3. 1.2 kb
4. 3.8 kb
5. 3.1 kb
After gel electrophoresis, what would be the order in which these fragments would be found—the last fragment listed being furthest from the negative pole.
a.
|
1,2,5,4,3
|
d.
|
3,2,4,5,1
|
b.
|
2,3,4,5,1
|
e.
|
1,4,5,3,2
|
c.
|
1,3,5,2,4
|
|
____ 90. The competency of bacterial cells to take up plasmids from the environment can be enhanced by treating them with calcium chloride. Which of the following statements is true regarding this process?
a.
|
Calcium ions neutralize charges on the phospholipids of the bacterial cell membrane and on the DNA of the plasmid.
|
b.
|
Chloride ions adhere to the cell membrane and calcium ions to the plasmid DNA, thus increasing the attractive force between them.
|
c.
|
Chloride ions neutralize charges on the phospholipids and DNA.
|
d.
|
Chloride ions enter the cell through protein pores in the membrane, carrying plasmid DNA with them.
|
e.
|
The calcium ions change the structure of the cell membrane and, as a result, the pores are enlarged.
|
____ 91. A plasmid was treated with a methylase enzyme and then with two restriction endonucleases. If the resulting DNA fragment(s) were run on a gel using electrophoresis, how many band(s) would you expect to see?
____ 92. The use of the hormone bovine somatotropin has not been approved in Canada. This is because
a.
|
tests showed that the hormone failed to boost milk production in cows experiencing long, cold Canadian winters
|
b.
|
there were concerns regarding the economic consequences to small dairy producers of the use of the hormone
|
c.
|
there were concerns that the hormone might contaminate the milk produced
|
d.
|
cows treated with the hormone grew so quickly that they were weakened and more susceptible to disease
|
e.
|
insufficient supplies of the hormone were available
|
____ 93. Two DNA primers are shown below
With which of the following strands of DNA could these primers be successfully used in the polymerase chain reaction?
1. 5'ATCGATTGGGCTTGGCA3'
|
|
2. 5'ACGGTTCGGGTTAGCTA3'
|
|
3. 3'TAGCTAACCCGAACCGT5'
|
|
4. 3'TGCCAAGCCCAATCGAT5'
|
|
|
a.
|
1 and 2
|
d.
|
3 and 4
|
|
b.
|
1 and 3
|
e.
|
1 and 4
|
|
c.
|
2 and 4
|
|
____ 94. All of the following are performed during restriction fragment length polymorphism analysis.
1. splitting of double-stranded into single-stranded DNA
|
2. gel electrophoresis
|
3. autoradiography
|
4. immersion in radioactive probes
|
5. digestion of DNA with restriction endonucleases
|
6. use of a positive charge to transfer single-stranded DNA from a gel to a membrane.
|
The correct sequence of these operations is
a.
|
5,1,2,6,4,3
|
d.
|
5,6,4,3,1,2
|
b.
|
5,1,2,6,3,4
|
e.
|
1,4,3,2,6,5
|
c.
|
5,2,1,6,4,3
|
|
____ 95. In the Sanger technique for sequencing DNA, growth of a newly synthesized strand of DNA requires
a.
|
radioactive nucleoside monophosphates
|
b.
|
nucleoside diphosphates
|
c.
|
dideoxynucleoside diphosphates
|
d.
|
nucleoside triphosphates
|
e.
|
only adenine triphosphate
|
____ 96. A fragment of DNA with a primer attached, which is going to be sequenced using the Sanger technique, is shown below.
5'ATGGAATTCGCCGATTGATT3'
|
3'
|
TAA 5'
|
How many different lengths of fragment will be produced in the reaction tube that contains a small proportion of dideoxycytosine triphosphate as well as cytosine triphosphate?
____ 97. Plant cells are hard to transform because they have
a.
|
a rigid cell wall
|
b.
|
more chromosomes than other life forms
|
c.
|
a rigid cell membrane
|
d.
|
more restriction endonucleases in their cells
|
e.
|
larger cells than other life forms
|
____ 98. When gel electrophoresis is undertaken, one well always contains DNA-marker molecules. The purpose of these markers is to
a.
|
serve as a guide to the length of the fragments in the other wells
|
b.
|
indicate when the DC current is turned on
|
c.
|
indicate when the DNA has completely crossed the gel
|
d.
|
help visualize the DNA
|
e.
|
serve as a channel for ethidium bromide
|
|
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