Solved by a verified expert:PASS MOCK EXAM – FOR PRACTICE ONLY
Course: BIOL 1103 A, N, T Facilitator:
1. Which of
the following processes can proceed in both the 5’ to 3’ direction and the 3’
to 5’ direction?
a. DNA gap
repair
b. DNA
transcription
c. DNA
translation
d. DNA
proofreading
e. None of
the above
2. Which of
the following is a correct match between monomer and polymer?
a. glucose
and lipids
b. amino
acids and polypeptide
c. nucleic
acids and protein
d. nucleotides
and lipids
e. none of
the above
3. A
compound that inhibits the activity of an enzyme without preventing the
substrate from binding to the enzyme is likely a(n):
a. Competitive
inhibitor
b. Noncompetitive
inhibitor
c. Allosteric
inhibitor
d. Feedback
inhibitor
e. Both (b)
and (c)
4. One of
the most efficient way in which cells are able to increase the level of
membrane fluidity is by:
a. Increasing
the number of phospholipids in the membrane
b. Decreasing
the number of glycolipids in the membrane
c. Decreasing
the number of double bonds between membrane lipids
d. Increasing
the number of desaturated phospholipids in the membrane
e. Increasing
the temperature of the membrane
5. Which of
the following types of transport is not energetically favourable but does not
require ATP
a. Simple
diffusion
b. Facilitated
diffusion
c. Primary
active transport
d. Secondary
active transport
e. Exocytosis
6. Each of
the following small molecules easily diffuses through the cell membrane EXCEPT:
a. glycerol
b. O2
c. H2O
d. glucose
e. N2
7. Which of
the following structure function pairs in mismatched?
a. nucleolus,
ribosome production
b. lysosome,
intracellular digestion
c. ribosome,
protein synthesis
d. golgi,
protein trafficking
e. microtubule,
muscle contraction
8. The process
by which mitochondria and chloroplasts probably evolved is called:
a. exocytosis
b. endocytosis
c. endogenous
translocation
d. exosymbiosis
e. endosymbiosis
9. In the
following reaction, the carbon atom of carbon dioxide is _______________ to
form glucose while the oxygen atom of water is _______________ to form oxygen:
6 CO2 + 6 H2O ? C6H12O6 + 6 O2
a. oxidized,
oxidized
b. oxidized,
reduced
c. reduced,
oxidized
d. reduced,
reduced
e. this
equation does not depict an oxidation- reduction reaction
10. Cellulose
is not good for human consumption because…
a. We cannot
hydrolyze the beta 1-4 linkage
b. We cannot
hydrolyze the beta 1-6 linkage
c. we
cannot hydrolyze the alpha 1-4 linkage
d. we cannot
hydrolyze the alpha 1-6 linkage
e. Cellulose
is good for human consumption
11. What are
the two secondary structures that amino acids form?
a. alpha
pleated sheets and beta-helix
b. alpha-helix
and gamma pleated sheets
c. alpha-helix
and beta pleated sheets
d. alpha
pleated sheets and gamma helix
e. chair and
boat conformations
12. Upon
chemical analysis, a particular protein was found to contain 59 amino acids.
How many peptide bonds are present in this protein?
a. 30
b. 58
c. 59
d. 60
e. The
secondary structure of the protein must be known to answer this question
13. If a piece
of double stranded DNA has 32% thymine, how much cytosine does it have?
a. 32%
b. 64%
c. 18%
d. 34%
e. It is
impossible to tell
14. If the ?G
of a chemical reaction is negative and the change in entropy is positive, what
can one conclude about the reaction?
a. It is
endergonic.
b. It is
exergonic.
c. It
requires energy.
d. It is
anabolic.
e. It will
not reach equilibrium.
15. The
Miller-Urey experiment…
a. Used an
atmosphere rich in O2
b. Demonstrated
that abiotic protein synthesis was possible
c. Did not
require a source of energy
d. Did not
require water as a reactant
e. Demonstrated
that abiotic synthesis of amino acids was possible
16. Which
statement about ATP synthesis is FALSE?
a. ATP is
synthesized only in chloroplasts and mitochondria
b. ATP
synthesis in the chloroplast occurs in the thylakoid region of this organelle
c. Proton
motive force (proton gradient) drives the formation of ATP in mitochondria
d. ATP
synthases are protein complexes that allow protons to cross membranes
e. Substrate
level phosphorylation of ADP does not require ATP synthase to catalyse the
reaction
17. Glycogen
is…
a. A type of
cholesterol
b. A Seine
molecule
c. Another
word for one glucose sugar
d. a
disaccharide made up of two glucose monomers
e. none of
the above
18. At the end
of glycolysis, each molecule of glucose has yielded 2 molecules of _______, 2
molecules of ________, and a net of 2 molecules of _________.
a. FAD;
NAD+; ADP
b. CO2;
NAD+; ADP
c. lactic
acid; ethanol; CO2
d. pyruvate,
NADH, ATP
e. H2O; CO2;
ATP
19. Explain
why in anaerobic cells the ratio of pyruvate/ lactate is much less than 1 while
under aerobic conditions the ratio of pyruvate/ lactate is much greater than 1.
a. under
anaerobic conditions pyruvate is converted to carbon dioxide
b. in anaerobic
conditions, pyruvate is converted to glucose using the energy of light
c. lactate
is produced from pyruvate only under anaerobic conditions
d. lactate
is the terminal electron acceptor under aerobic conditions
e. pyruvate
is transported into mitochondria under anaerobic conditions
20. In the
absence of oxygen, the primary purpose of fermentation is to:
a. produce
amino acids for protein synthesis
b. generate
a proton gradient for ATP synthesis
c. oxidize
glucose to generate reduce electron carriers
d. regenerate
NAD+ from NADH allowing glycolysis to continue
e. generate
alcohol for beverages
21. Which of
the following statements about mitochondria is false?
a. They
contain an inner and an outer membrane.
b. The
region enclosed by the inner membrane is termed the matrix.
c. They
contain DNA and ribosomes.
d. They are
an important site for energy production in cells.
e. They
contain stacked internal grana.
22. The
electron transport chain is located predominantly in the:
a. Outer
membrane of the mitochondria
b. Intermembrane
space of the mitochondria
c. Inner
membrane of the mitochondria
d. Matrix of
the mitochondria
e. Cytoplasm
of the cell
23. What
cellular compartment becomes acidic during mitochondrial electron transport?
a. Mitochondrial
stroma
b. Cytoplasm
c. Endoplasmic
reticulum
d. Space
between inner and outer mitochondrial membranes
e. Thylakoid
membranes
24. As a
result of glycolysis, pyruvate oxidation and the citric acid cycle, only a
small portion of the energy of glucose has been converted to ATP. At this
point, the majority of the usable energy is contained in:
a. oxidized
electron carriers NAD+ and FAD
b. carbon
dioxide
c. pyruvate
d. acetyl
coenzyme A
e. reduced
electron carriers NADH and FADH2
25. The
terminal electron acceptor during mitochondrial respiration is:
a. H20
b. NAD+
c. FAD
d. ATP
e. O2
26. During a
heart attack, blood flowing to the heart muscle is interrupted by blockage of a
coronary artery. How would you expect the metabolism in the heart to change?
a. oxidative
phosphorylation would slow down in the mitochondria
b. the rate
of production of lactic acid would be stimulated
c. the use
of glucose by the muscle tissue would increase
d. the
production of water by mitochondria would be inhibited
e. all are
expected metabolic changes
27. In the
first step of glycolysis, the enzyme hexokinase uses ATP to transfer a
phosphate to glucose to form glucose-6-phosphate. The product continues to be
oxidized forming pyruvate in glycolysis and is a precursor to acetyl-CoA for
the citric acid cycle. Suppose that a cell has only glucose available for
energy and that the activity of hexokinase is suddenly stopped in this cell.
Which of the following conditions will occur?
a. The cell
will continue to produce energy from mitochondrial electron transport.
b. The cell
will continue to produce ATP using the citric acid cycle.
c. The cell
will ultimately be unable to produce ATP.
d. The cell
will be forced to switch to fermentation to produce ATP.
e. The use
of oxygen by the cell will increase.
28. During the
light phase of photosynthesis __________ is oxidized and __________ is reduced.
a. CO2 and
Water
b. Water and
CO2
c. Water
and NADP
d. NADPH2
and CO2
e. ADP and
NAD+
29. The oxygen
molecule in glucose formed during photosynthesis comes from:
a. Water
b. Organic
acids
c. CO2
d. Atmospheric
gases
e. Oxygen
produced in the chloroplasts
30. With
regard to the enzyme rubisco, oxygen…
a. Is an
allosteric activator of the enzyme.
b. Is a
competitive inhibitor.
c. Helps
prevent photorespiration.
d. Increases
the catalytic efficiency of the carboxylation reaction.
e. Is
produced when rubisco “splits” water.
31. Unidirectional
flow of electrons in non-cyclic photophosphorylation can be denoted as follows:
a. PS II —
e- —> PS I — e- —> NADP — e- —> water
b. Water —
e- —> PSII — e- —> PS I — e- —> NADP
c. PS I —
e- —> NADP — e- —> water —
e- —> PS II
d. Water —
e- —> PS I — e- —> PS II —
e- —> NADP
e. Oxygen —
e- —> PS II — e- —> PS I —
e- —> ATP
32. Chlorophyll-a
differs from chlorophyll-b in having:
a. A methyl
group instead of aldehyde group
b. An
aldehyde group instead of methyl group
c. A methyl
group instead of ethyl group
d. Only a
phytol tail instead of head
e. A ketone
group instead of a methyl group
33. ____________
are placed one above the other to form stack of pancakes known as a granum.
a. oxysomes
b. F1
particles
c. cristae
d. thylakoids
e. chloroplasts
34. In C4
plants, the Calvin cycle operates in:
a. Stroma of
bundle sheath chloroplasts
b. Grana of
Bundle sheath chloroplasts
c. Grana of
mesophyll chloroplasts
d. Stroma of
mesophyll chloroplasts
e. Lumen of
palisade chloroplasts
35. How many
ATP, FADH2, and NADH molecules per acetyl CoA are produced during the citric
acid cycle?
a. 1: 1: 3
b. 2: 2: 6
c. 3: 1: 1
d. 6: 2: 2
e. 1: 1: 2
36. Consider
the following diagram of the cell cycle. Which of the following statements is
true?
a. mitosis
is represented by V
b. G0 is
represented by I
c. chromosomes
are comprised of 2 sister chromatids during I and V
d. the
chromosomes are replicated during II
e. G2 is
represented by I
37. Which kind
of protein is responsible for regulating the cell cycle?
a. Kintetochores
b. Cyclins
c. Catalytic
Enzymes
d. Centrosomes
e. Keratins
38. Bacteria
grown in a heavy nitrogen medium are allowed two cycles of replication in a
light nitrogen medium. After centrifugation, how many levels of DNA density can
be found?
a. 1
b. 2
c. 3
d. 0
e. It is
impossible to tell
39. Which of
the following is a true statement regarding DNA transcription?
a. Active
transcription is generally associated with heterochromatin.
b. Adding
acetyl groups to heterochromatin will create euchromatin.
c. Methylating
heterochromatin will produce euchromatin, which can be transcribed.
d. Adding a
CHO group to heterochromatin will allow heterochromatin to be transcribed.
e. DNA can
only be transcribed upon removal of the histone proteins.
40. Which of
the following types of RNA is/are translated?
a. mRNA
b. rRNA
c. tRNA
d. miRNA
e. (a) and
(d) only
41. What does
it mean to say that the genetic code is “degenerate”?
a. More than
one amino acid encodes each codon
b. DNA
degrades quickly, and so must constantly be replicated
c. More
than one codon encodes each amino acid
d. Only one
codon encodes each amino acid
e. DNA is
tends to accrue mutations over time
42. Newly
synthesised secretory proteins contain a signal sequence. The function of which
is…
a. to direct
an mRNA molecule into the cisternal space of the endoplasmic reticulum
b. to
facilitate attachment of ribosomes synthesizing the protein to the endoplasmic
reticulum
c. to
terminate translation of the mRNA and cause the protein to dissociate from the
ribosome
d. to signal
the initiation of transcription
e. Answers
(a) & (d) are both correct
43. As you are
writing this mock exam, you are breathing in O2 and breathing out CO2. The CO2
arises from the
a. Oxidation
of acetyl-CoA by the citric acid cycle.
b. Conversion
of glucose to pyruvate during glycolysis.
c. Conversion
of pyruvate to acetyl-CoA.
d. Oxditative
phosphorylation.
e. Both (a)
and (c) are correct
Answer questions 44-49 using the table above and the
following template strand of DNA:
3’-GCTACCCGATGTACGGAGTCACTATTG-5’
44. If the
sequence above were transcribed, which of the following mRNA sequences would be
produced?
a. 3’-
CGAUGGGCUACAUGCCUCAGUGAUAAC-5’
b. 5’-
CGAUGGGCUACAUGCCUCAGUGAUAAC-3’
c. 3’-
GCUACCCGAUGUACGGAGUCACUAUUG-5’
d. 5’- GCU
ACC CGA UGU ACG GAG UCA CUA UUG-3’
e. 5’-
CGATGGGCTACAUGCCTCAGTGATAAC-3’
45. If this
mRNA sequence is in a eukaryote, what is the name of the enzyme which would
transcribe the sequence?
a. RNA
polymerase
b. RNA
polymerase II
c. DNA
polymerase
d. DNA
polymerase II
e. Ribosome
46. If the
mRNA sequence were then translated, which of the following polypeptide chains
would be produced?
a. Arg-Trp-Ala-Thr-Cys-Leu-Ser-Asp-Asn
b. Met-
Arg-Trp-Ala-Thr-Cys-Leu-Ser-Asp-Asn
c. Ala-Thr-Arg-Cys-Thr-Glu-Ser-Leu-Leu
d. Met-Gly-Tyr-Met-Pro-Gln
e. Met-Tyr-Gly-Val-Thr-Ile
47. Which of
the following is a possible anticodon sequence of the tRNA which could deliver
methionine to the growing polypeptide chain?
a. 3’-TAC-5’
b. 5’-TAC-3’
c. 3’-AUG-5’
d. 5’-AUG-3’
e. 3’-ATG-5’
48. If the DNA
sequence were mutated, such that the second thymine in the sequence became a
guanine, what sequence polypeptide sequence would be produced?
3’-GCTACCCGAGGTACGGAGTCACTATTG-5’
a. Met-Tyr
b. Met-Arg-Trp-Ala-Pro-Cys-Leu-Ser-Asp-Asn
c. Arg-Trp-Ala-Pro-Cys-Leu-Ser-Asp-Asn
d. Ala-Thr-Arg
e. Met-Gly-Ser-Met-Pro-Gln
49. What type
of mutation is the mutation in question 48?
a. Silent
mutation
b. Missense
mutation
c. Nonsense
mutation
d. Frameshift
mutation
e. Replacement
mutation
50. A gene
that normally encodes for a protein that is 65000 g/mol in mass is exposed to a
hazardous chemical. After it is transcribed into a protein, it is found that
the protein is 15000 g/mol in mass. What kind of mutation likely occurred?
a. Nonsense
b. Missense
c. Frameshift
d. Silent
e. Continuous
51. A chemical
that impairs the ability of spindle fibres to function normally in a diploid
cell would likely result in offspring in the F1 generation that are:
a. Polyploid
b. Diploid
c. Large
d. Recombined
e. Haploid
52. Could a
type O blood type father ever have an offspring with blood type AB?
a. Yes, but
only if the mother has type AB blood
b. Yes, but
only if the mother also has type O blood
c. Yes, but
only if the father is RH(d) negative
d. Yes, but
only if the mother is RH(d) negative.
e. No
53. In humans,
males are…
a. Homogametic
b. Heterogametic
c. Hemigametic
d. Hermaphroditic
e. pseudohermaphroditic
54. The
dominant C allele of a gene that controls colour in corn produces kernels with
colour; plants homozygous for a recessive c allele of this gene have colourless
or white kernels. If a CC plant and a Cc plant were crossed, what would be the
expected phenotypic ratios of the offspring?
a. 1
coloured kernels: 1 white kernels
b. 3
coloured kernels: 1 white kernels
c. 1
coloured kernels: 3 white kernels
d. 4
coloured kernels: 0 white kernels
e. It is
impossible to tell
55. A
researcher crosses plants that are heterozygous for the dominant ‘tall’ trait
and the recessive ‘short’ trait. 585 plants in the F1 generation are tall.
Approximately how many plants in the F1 generation would you expect to be
short?
a. 195
b. 585
c. 146
d. 780
e. 245
56. In
Mendel’s experiments, the spherical seed character (SS) is completely dominant
over the dented seed character (ss). If the characters for height were
incompletely dominant, such that TT are tall, Tt are intermediate and tt are
short, what would be the phenotypes resulting from crossing a spherical-seeded,
short (SStt) plant to a dented-seeded, tall (ssTT) plant?
a. All the
progeny would be spherical-seeded and tall.
b. 1/2 would
be spherical-seeded and intermediate height; 1/2 would be spherical-seeded and
tall.
c. All the
progeny would be spherical-seeded and short.
d. You
cannot predict the outcome.
e. All the
progeny would be spherical-seeded and intermediate height.
57. Two
unlinked loci effect mouse hair color. AA or Aa mice are agouti. Mice with
genotype aa are albino because all pigment production is blocked, regardless of
the phenotype at the second locus. At the second locus, the B allele (agouti
coat) is dominant to the b allele (black coat). What would be the result of a
cross between two agouti mice of genotype AaBb?
a. 4 agouti:
4 black: 8 albino
b. 9 agouti:
3 black: 3 albino: 1 grey
c. 9
agouti: 3 black: 4 albino
d. 8 agouti:
4 black: 4 albino
e. None of
the above
58. In guinea
pigs, an allele for rough fur is dominant over an allele for smooth fur; an
allele for black coat is dominant over that for white. You have an animal with
rough, black fur. What cross would you use to determine whether the animal is
homozygous for these traits?
a. Cross the
animal with a rough, black fur individual.
b. Cross the
animal with a rough, white fur individual.
c. Cross
the animal with a smooth, black fur individual.
d. Cross the
animal with a smooth, white fur individual.
e. Two
generations of crosses are required to determine whether the animal is
homozygous for these traits.
59. If
freckles were coded by an autosomal dominant gene and one parent had freckles,
what percentage of the offspring would have freckles?
a. 50%
b. 25%
c. 100%
d. 75%
e. More
information is required in order to accurately answer this question.
60. If a
Drosophila melanogaster that is heterozygous for two genes (phenotype short
haired and curly winged) is crossed with an organism that is homozygous
recessive for the genes (phenotype long haired and normal winged) and the
resultant F1 generation is composed of 157 short haired curly winged, 685 short
haired normal winged, 148 normal haired curly winged, and 672 normal haired
curly winged, what does this tell you about the genes?
a. These
genes are all found at the same loci.
b. These
genes assorted independently.
c. These
genes are likely located close to each other on the same chromosome, making
them linked.
d. These
genes assorted independently and they are likely located close to each other on
the same chromosome.
e. No
information can be gathered about the genes location, but information regarding
which traits are dominant is now known.
61. Using the
results for the F1 generation above (in question 60), the allele for hair
length and wing shape are how many map units apart?
a. 32
b. 18
c. 78
d. The genes
are not on the same chromosome
e. It is
impossible to tell
62. If a
father passes a genetically dominant disease on to his son, it cannot have a(n)
_____________ inheritance pattern.
a. Autosomal
dominant
b. Autosomal
recessive
c. Sex-linked
recessive
d. None of
the above
e. A father
cannot pass a genetically inheritable disease to his sons, he can only pass on
a disease to his daughters
63. In a
dihybrid cross, SsYy x SsYy, what fraction of the offspring will be homozygous
for both traits?
a. 1/16
b. 1/8
c. 3/16
d. 1/4
e. 3/4
64. What
offspring would you expect from a cross between the female Drosophila with red
eyes and a yellow body (homozygous recessive for the yellow body color allele
and homozygous dominant for the eye colour allele) and a male fruit fly with
white eyes and a tan body (hemizygous for both the recessive (white) eye color
allele and dominant (tan) body color allele.
The alleles for eye color and for body color are on the X
chromosome of Drosophila. Red eye color (w+) is dominant to white eye color
(w), and tan body color (y+) is dominant to yellow body color (y).
a. Daughters
would be yellow-bodied, red-eyed; the sons would be tan-bodied, white-eyed
b. Daughters
would be tan-bodied, red-eyed; the sons would be yellow-bodied, white-eyed
c. Daughters
would be tan-bodied, red-eyed; the sons would be yellow-bodied, red-eyed
d. Daughters
would be yellow-bodied, white-eyed; the sons would be tan-bodied, white-eyed
e. Daughters
would be yellow-bodied, red-eyed; the sons would be tan-bodied, red-eyed
65. Individuals
with three copies of most autosomes do not survive. Individuals with an extra X
chromosome, however, survive with relatively mild (compared to autosomal
abnormalities) consequences. Why?
a. The X
chromosome contains few genes while autosomes contain a large number
b. The extra
X chromosome(s) are inactivated
c. The X
chromosome determines sex only
d. This is
not true, individuals would not survive with three X chromosomes
e. none of
the above
66. Consider a
parental cross AABBCc x AabbCc. Assume complete dominance and independent
assortment. What proportion of the progeny will be expected to phenotypically
resemble the AABBCc parent?
a. 1/4
b. 1/8
c. 3/4
d. 1
e. 3/8
67. Assuming
equal sex ratios, if a mating has already produced 3 girls, what is the
probability that the next child will be a girl?
a. 0
b. 1
c. 1/2
d. (1/2)3
e. 1 ?
(1/2)3
68. During
conjugation, the purpose of the sex pilus is to…
a. Facilitate
the movement of nutrients between a donor and a recipient cell.
b. Allow for
the transfer of gametes.
c. Facilitate
DNA exchange between a donor cell and a recipient cell.
d. Stabilize
a network of bacterial cells.
e. Facilitate
the movement of pollen from the anther to an egg situated in the ovule.
69. Centromeres
of sister chromatids uncouple and chromatids separate during…
a. Anaphase
of Meiosis I
b. Anaphase
of Meiosis II
c. Anaphase
of Mitosis
d. Answers (b)
and (c) are both correct.
e. All of
the above are correct.
70. A
principle difference between Prophase I of meiosis and prophase of mitosis is
that…
a. Tetrads
form in prophase I of meiosis but not during prophase of mitosis
b. The
chromosomes are highly condensed only during prophase I of meiosis
c. In
prophase I of meiosis, homologous chromosomes separate, wheras in prophase of
mitosis, sister chromatids separate
d. A spindle
apparatus forms in prophase of mitosis, but not during prophase I of meiosis.
e. Answers
(a) and (d) are both correct.
71. Which of
the following is a DNA sequence?
a. Coactivator
b. Corepressor
c. Enhancer
d. Inducer
e. Transactivator
72. In the
fruit fly, the dominant and recessive traits for body colour and wing size are
as follows:
Character Wild
Type / Dominant Trait Mutant /
Recessive Trait
Body Colour Grey
(b+) Black (b)
Wing Size Normal
(vg+) Vestigial (vg)
The genes encoding body colour and wing size are linked.
A wild-type fruit fly (heterozygous for grey body colour and
normal wings) was mated with a black fruit fly with vestigial wings. The
distribution of the offspring is as follows:
802 – Wild Type
798 – Black with vestigial wings
206 – grey with vestigial wings
194 – black with normal wings
What is the recombination frequency between the genes for
body colour and wing size?
a. 10%
b. 20%
c. 40%
d. 80%
e. There is
no recombination
73. Genetic
differences in prokaryotic cells will arise as a result of:
a. Mutations
arising during DNA replication
b. Unequal
crossing over and recombination during prophase I
c. Independent
assortment of chromosomes during meiosis I
d. Recombination
between the recipient chromosome and DNA entering the cell through
transformation, conjugation and transduction.
e. Answers
(a) and (d) are both correct.
74. Which of
the following is a characteristic of all viruses?
a. a protein
capsid
b. nucleic acid
genome
c. glycoprotein
cell wall
d. (a) and
(b) only
e. All of
the above
75. Double-stranded
viruses can reproduce the lytic cycle and the lysogenic cycle. Which of the
following is characteristic of the lytic cycle?
a. The viral
genome replicates without destroying the host
b. The
virus-host relationship usually lasts for generations
c. Many
bacterial cells containing viral DNA are produced
d. Viral DNA
is incorporated into the host chromosomes
e. A large
number of phages are released at a time
76. Bacteriophage
DNAs that have become integrated into the host cell chromosome are called:
a. plasmids
b. T-even
bacteriophages
c. prophages
d. transposons
e. intemperate
bacteriophage
77. An Hfr
bacterium is one that has:
a. A plasmid
that has become integrated into its chromosome
b. Several
copies of a single transposon repeated randomly throughout its chromosome
c. Several
insertion sequences scattered throughout its chromosome
d. A special
recognition site that will take up closely related DNA from its environment
e. At least
one plasmid present in the cytosol
78. Which of
the following statements correctly describes promoters in E. coli?
a. promoter
may be present on either side of a gene or in the middle of it
b. All
promoters have the same sequence that is recognized by RNA polymerase
holoenzyme
c. Every
promoter has a different sequence, with little or no resemblance to other
promoters
d. Many
promoters are similar and resemble a consensus sequence, which has the highest
affinity for RNA polymerase holoenzyme
e. Promoters
are not essential for gene transcription, but can increase its rate by two- to
three-fold
79. What is
the function of the operator locus of the lactose operon?
a. Terminate
production of repressor molecules
b. Initiate
production of mRNA
c. Identify
the substrate allolactose
d. Bind
steroid hormones and control translation
e. Control
the binding of RNA polymerase to the operator region
80. When is
the lactose operon likely to be transcribed? When…
a. There is
more lactose in the cell than glucose
b. There is
more glucose in the cell than lactose
c. There is
lactose but no glucose in the cell
d. The
cyclic AMP levels are high within the cell
e. Both (c)
and (d) are correct
81. The
interaction between non?allelic genes in their effects on a trait is called:
a. epistasis
b. epigenetics
c. dominance
d. codominance
e. incomplete
dominance
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