Instructions
Select the correct answer for the 70 multiple choice questions by highlighting the correct answer
1. Item 1
Enzymes:
A. increase the energy of activation for a reaction, thus increasing the reaction rate.
B. decrease the energy of activation for a reaction, thus decreasing the reaction rate.
C. increase ΔG for a reaction, thus increasing the reaction rate.
D. decrease the energy of activation for a reaction, thus increasing the reaction rate.
E. decrease ΔG for a reaction, thus increasing the reaction rate.
1. Item 2
Hemophilia is an X-linked recessive disorder involving blood clotting. If a Mr. Y, who is a hemophiliac, marries Mrs. Z, who is a carrier for hemophilia, and one of their daughters (Miss A, who is not a hemophiliac) marries a normal man (Mr. B), what is the probability that a grandson of Mr. Y and Mrs. Z is a hemophiliac?
A. 25% B. 50% C. 75% D. 100% E. Cannot be determined from the information given
1. Item 3
All of the following could cause increases in resting blood pressure EXCEPT:
A. increased Na+ reabsorption by the kidney.
B. increased heart rate.
C. decreased dehydration.
D. caffeine.
E. None of the above.
1. Item 4
The functions of the liver include all of the following EXCEPT:
A. formation of blood proteins.
B. regulation of glycogen metabolism.
C. secretion of bile.
D. storage of vitamins.
E. secretion of bicarbonate.
1. Item 5
Osteoblasts, osteoclasts, and osteocytes are the three cell types found in bone tissue. Osteoclasts are activated by:
A. low blood Ca2+ levels and high parathyroid hormone levels.
B. low blood Ca2+ levels and high calcitonin levels.
C. high blood Ca2+ levels and high calcitonin levels.
D. high blood Ca2+ levels and high vitamin D levels.
E. low blood Ca2+ levels and low parathyroid hormone levels.
1. Item 6
Which hormone binds to a receptor on the cell surface?
A. Aldosterone
B. Progesterone
C. Cortisol
D. Adrenaline
E. Testosterone
1. Item 7
Which of the following RNA sequences would be transcribed if the sequence of the DNA coding strand were TATTGCATCAA?
A. UAUUGCAUCAA
B. AUAACGUAGUU
C. TTGUTGCUUTU
D. AUAAGCAUCAA
E. UUGAUCGUUAU
1. Item 8
The pentose phosphate pathway is involved in all of the following EXCEPT:
A. eliminating reactive oxygen species.
B. producing nucleotides.
C. facilitating fatty acid synthesis.
D. forming NADH.
E. generating ribose-5-phosphate.
1. Item 9
When blood pressure is low, the rate of blood filtration drops. The kidney secretes renin to help compensate. The direct effect that renin has in the body is to:
A. generally constrict arterioles to increase peripheral resistance.
B. convert the blood protein angiotensinogen into angiotensin I.
C. convert angiotensin I into angiotensin II, a powerful vasoconstrictor.
D. dilate the renal artery.
E. dilate the glomerular capillaries.
1. Item 10
In designing antibiotics to treat infections caused .
Instructions Select the correct answer for the 70 multiple choic.docx
1. Instructions
Select the correct answer for the 70 multiple choice questions
by highlighting the correct answer
1. Item 1
Enzymes:
A. increase the energy of activation for a reaction, thus
increasing the reaction rate.
B. decrease the energy of activation for a reaction, thus
decreasing the reaction rate.
C. increase ΔG for a reaction, thus increasing the reaction rate.
D. decrease the energy of activation for a reaction, thus
increasing the reaction rate.
E. decrease ΔG for a reaction, thus increasing the reaction rate.
1. Item 2
Hemophilia is an X-linked recessive disorder involving blood
clotting. If a Mr. Y, who is a hemophiliac, marries Mrs. Z, who
is a carrier for hemophilia, and one of their daughters (Miss A,
who is not a hemophiliac) marries a normal man (Mr. B), what
is the probability that a grandson of Mr. Y and Mrs. Z is a
hemophiliac?
A. 25% B. 50% C. 75% D. 100% E. Cannot be determined
from the information given
1. Item 3
All of the following could cause increases in resting blood
pressure EXCEPT:
A. increased Na+ reabsorption by the kidney.
B. increased heart rate.
C. decreased dehydration.
D. caffeine.
E. None of the above.
2. 1. Item 4
The functions of the liver include all of the following EXCEPT:
A. formation of blood proteins.
B. regulation of glycogen metabolism.
C. secretion of bile.
D. storage of vitamins.
E. secretion of bicarbonate.
1. Item 5
Osteoblasts, osteoclasts, and osteocytes are the three cell types
found in bone tissue. Osteoclasts are activated by:
A. low blood Ca2+ levels and high parathyroid hormone levels.
B. low blood Ca2+ levels and high calcitonin levels.
C. high blood Ca2+ levels and high calcitonin levels.
D. high blood Ca2+ levels and high vitamin D levels.
E. low blood Ca2+ levels and low parathyroid hormone levels.
1. Item 6
Which hormone binds to a receptor on the cell surface?
A. Aldosterone
B. Progesterone
C. Cortisol
D. Adrenaline
E. Testosterone
1. Item 7
Which of the following RNA sequences would be transcribed if
the sequence of the DNA coding strand were TATTGCATCAA?
A. UAUUGCAUCAA
B. AUAACGUAGUU
C. TTGUTGCUUTU
D. AUAAGCAUCAA
E. UUGAUCGUUAU
1. Item 8
The pentose phosphate pathway is involved in all of the
3. following EXCEPT:
A. eliminating reactive oxygen species.
B. producing nucleotides.
C. facilitating fatty acid synthesis.
D. forming NADH.
E. generating ribose-5-phosphate.
1. Item 9
When blood pressure is low, the rate of blood filtration drops.
The kidney secretes renin to help compensate. The direct effect
that renin has in the body is to:
A. generally constrict arterioles to increase peripheral
resistance.
B. convert the blood protein angiotensinogen into angiotensin I.
C. convert angiotensin I into angiotensin II, a powerful
vasoconstrictor.
D. dilate the renal artery.
E. dilate the glomerular capillaries.
1. Item 10
In designing antibiotics to treat infections caused by facultative
anaerobic bacteria in humans, the targets which would be most
attractive are inhibitors of bacterial:
A. mRNA splicing.
B. electron transport.
C. poly-A addition for mRNAs.
D. transcription.
E. None of the above.
1. Item 11
A double homozygous dominant rabbit with bent ears and big
feet is crossed with a double homozygous recessive rabbit with
straight ears and small feet. One of the F1s is backcrossed to
the double homozygous recessive parent producing an F2
generation with the following ratios of phenotypes: 15 rabbits
with bent ears and big feet, 15 rabbits with straight ears and
4. small feet, 5 rabbits with bent ears and small feet, and 5 rabbits
with straight ears and big feet. What is the recombination
frequency between the gene for ear position and the gene for
foot size?
A. 12.5%
B. 25%
C. 33.3%
D. 50%
E. 66.7%
1. Item 12
During muscle contraction, which regions of the sarcomere
shorten?
I. A band II. I band III. H band
A. II only
B. I and II only
C. II and III only
D. I and III only
E. I, II, and III
1. Item 13
Which cells in the testes are responsible for secretion of
testosterone?
A. Sustentacular (Sertoli) cells
B. Spermatogonia
C. Supporting cells
D. Interstitial (Leydig) cells
E. None of the above secrete testosterone.
1. Item 14
What is the primary effect of transposons?
A. Generate mutations and chromosomal rearrangements
B. Facilitate recombination during meiosis
C. Provide protection against integration of lysogenic viruses
D. Increase the affinity of RNA polymerase binding to a
promoter
5. E. Conduct DNA replication proofreading
1. Item 15
The volume of air that remains in the lungs after a complete
expiration is called the:
A. residual volume.
B. expiratory reserve volume.
C. functional residual capacity.
D. vital capacity.
E. tidal volume.
1. Item 16
All of the following are methods by which bacteria can achieve
genetic diversity EXCEPT:
A. conjugation.
B. binary fission.
C. transformation.
D. transduction.
E. recombination.
1. Item 17
The dendrites of a single postsynaptic neuron often form
synapses with axons of many different presynaptic neurons. The
combined input of all the presynaptic neurons ultimately
determines whether the postsynaptic neuron will fire an action
potential or not. This is known as:
A. facilitation.
B. integration.
C. cooperativity.
D. temporal summation.
E. spatial summation.
1. Item 18
A hospital has possibly switched the babies of Couples X and Y.
Their blood types are as follows:
Couple X: type A and type A Baby 1: type O
6. Couple Y: type AB and type O Baby 2: type B
Which baby belongs to which couple?
A. Both babies belong to Couple Y.
B. Baby 1 belongs to Couple Y and Baby 2 belongs to Couple
X.
C. Baby 1 belongs to Couple X, but Baby 2 could belong to
either couple.
D. Baby 1 belongs to Couple X and Baby 2 belongs to Couple
Y.
E. Baby 2 belongs to Couple Y, but Baby 1 does not belong to
either couple.
1. Item 19
If red blood cells are placed in pure water, which of the
following would occur?
A. The cells would swell due to the high osmotic pressure of
the water.
B. The cells would shrink due to the high osmotic pressure of
the cells.
C. The cells would neither shrink nor swell because red blood
cells are isotonic to water.
D. The cells would swell because they are hypotonic to the
water.
E. None of the above would occur.
1. Item 20
The net products of glycolysis per glucose molecule are:
A. 4 ATP, 2 NADH, 2 pyruvate
B. 2 ATP, 2 NADH, 2 pyruvate
C. 2 ATP, 4 NADH, 2 lactate
D. 4 ATP, 4 NADH, 4 pyruvate
E. 2 ATP, 2 NADH, 2 lactate
1. Item 21
The hair cells on the basilar membrane represent which of the
following receptor types?
7. A. Baroreceptor
B. Thermoreceptor
C. Mechanoreceptor
D. Chemoreceptor
E. Nociceptor
1. Item 22
Which of the following cells are produced by the first meiotic
division of oogenesis?
A. Oogonium
B. Primary oocyte and first polar body
C. Secondary oocyte and first polar body
D. Secondary oocyte and second polar body
E. Mature ovum and second polar body
1. Item 23
Potassium moving down its concentration gradient through
K+channels in the plasma membrane is an example of:
A. simple diffusion.
B. active transport.
C. exocytosis.
D. osmosis.
E. facilitated diffusion.
1. Item 24
All of the following can be observed during both meiosis and
mitosis EXCEPT:
A. alignment of chromosomes on the metaphase plate.
B. separation of sister chromatids.
C. synapsis of homologous chromosomes.
D. cytokinesis.
E. dissolution of the nuclear membrane.
1. Item 25
The opening of which type of ion channel initiates an action
potential?
8. A. Voltage-gated Na+
B. K+ leak
C. Voltage-gated K+
D. Voltage-gated Ca2+
E. Na+/K+ pump
1. Item 26
All of the following are true about Gram– bacteria EXCEPT:
A. they have thin cell walls.
B. they have an inner plasma membrane.
C. they stain a dark purple in Gram stain.
D. they are more resistant to antibiotics than Gram+ bacteria.
E. they have a layer of plasma membrane outside the cell wall.
1. Item 27
When measuring reaction velocity as a function of substrate
concentration, a researcher usually keeps the concentration of
enzyme at a constant level. What would happen if the enzyme
concentration were NOT kept constant?
A. Vmax would remain constant, but V would change.
B. Vmax would remain constant, but Km would change.
C. Vmax would change, but Km would remain constant.
D. both Vmax and Km would change.
E. None of the above would necessarily occur.
1. Item 28
What role does p53, a typical product of a tumor suppressor
gene, play in the cell?
A. Signal CD4 T cells to destroy a cell infected with a cancer-
causing virus
B. Upregulate transcription of protooncogenes
C. Promote chemotaxis and diapedesis of the cell
D. Trigger apoptosis if abnormal cell growth cannot be halted
E. Stimulate production of additional mitochondria
1. Item 29
9. Which of the following correctly lists functions of the
sympathetic nervous system?
A. Dilate pupils, reduce heart rate, increase blood pressure,
inhibit GI tract
B. Increase heart rate, constrict pupils, decrease blood
pressure, inhibit GI tract
C. Increase blood pressure, dilate pupils, dilate bronchial
tubes, increase heart rate
D. Inhibit GI tract, increase heart rate, constrict bronchial
tubes, increase blood pressure
E. Dilate bronchial tubes, stimulate GI tract, increase heart rate,
constrict pupils
1. Item 30
All of the following statements about DNA replication are true
EXCEPT:
A. it occurs in the 5′ to 3′ direction.
B. both new strands are replicated continuously along the
parent strands.
C. prokaryotes use five different DNA polymerases.
D. it requires an RNA primer.
E. it is semiconservative.
1. Item 31
A virus infects a cell and immediately induces the cellular
machinery to produce new viral particles. These new viruses
exit the cell by budding through the cell membrane. Which of
the following is true about this virus?
A. It is a plant virus involved in a lytic cycle.
B. It is a bacterial virus involved in a lysogenic cycle.
C. It is a plant virus involved in a productive cycle.
D. It is an animal virus involved in a lytic cycle.
E. It is an animal virus involved in a productive cycle.
1. Item 32
The structure that secretes progesterone during the menstrual
10. cycle is the:
A. oocyte.
B. ovary.
C. developing follicle.
D. corpus luteum.
E. uterus.
1. Item 33
Which of the following lists organelles that have only a single
membrane?
A. Nucleus, rough ER, mitochondria
B. Mitochondria, Golgi apparatus, rough ER C. Lysosome,
Golgi apparatus, nucleus
D. Golgi apparatus, rough ER, lysosome
E. Mitochondria, lysosome, rough ER
1. Item 34
Which intermediate of cellular respiration is NOT part of
gluconeogenesis?
A. Oxaloacetate
B. Phosphoenolpyruvate
C. Dihydroxyacetone-phosphate
D. Fructose-6-phosphate
E. Acetyl-CoA
1. Item 35
Which of the following sensory receptors are NOT
mechanoreceptors?
A. Aortic baroreceptors
B. Hearing receptors in the Organ of Corti
C. Rods and cones
D. Pacinian corpuscles
E. Golgi tendon organs
1. Item 36
The hormone responsible for raising blood glucose levels
between meals is:
11. A. glucagon.
B. insulin.
C. epinephrine.
D. ACTH.
E. none of the above.
1. Item 37
A woman who is heterozygous for brown eyes (blue is
recessive) and heterozygous for brown hair (blond is recessive)
marries a man who has blond hair and is heterozygous for
brown eyes. What is the probability they will have a son who
has brown hair and brown eyes, and who is capable of fathering
children with blue eyes?
A. 1/4
B. 1/2
C. 1/8
D. 1/16
E. This cannot be determined from the information given.
1. Item 38
The ion channel responsible for the plateau of the cardiac
muscle cell action potential is the:
A. Na+ leak.
B. K+ leak.
C. voltage-gated Na+.
D. voltage-gated K+.
E. voltage-gated Ca2+.
1. Item 39
The functions of the large intestine include all of the following
EXCEPT:
A. fecal storage.
B. reabsorption of water.
C. production of vitamin K by intestinal bacteria.
D. digestion and absorption of nutrients not fully digested in the
small intestine.
12. E. reabsorption of electrolytes.
1. Item 40
During which phase of the ovarian cycle are increasing levels of
estrogen secreted?
A. Secretory phase
B. Follicular phase
C. Ovulatory phase
D. Menstrual phase
E. Proliferative phase
1. Item 41
Telomerases are important in the replication of eukaryotic DNA
because they:
A. connect leading and lagging strand fragments to create a
contiguous linear chromosome.
B. remove methyl groups from protected sequences to allow
replication.
C. generate the repetitious DNA sequences at the end of linear
chromosomes.
D. provide primers for leading strand synthesis.
E. unwind the double helix for replication to begin.
1. Item 42
In the absence of ATP, which step(s) of the sliding filament
theory CANNOT occur?
I. Myosin head groups attach to actin. II. Myosin “power
stroke” pulls actin toward center of sarcomere. III. Myosin
releases actin. IV. Myosin head groups are cocked back to
“reset” to original position.
A. II only
B. II and III only
C. III and IV only
D. I and II only
E. II, III, and IV only
13. 1. Item 43
Which of the following structures are NOT made of
microtubules?
A. Microvilli
B. Mitotic spindle
C. Flagella
D. Cilia E. Centrioles
1. Item 44
Which blood vessel carries oxygenated blood to the left atrium
of the heart?
A. Aorta
B. Pulmonary artery
C. Pulmonary vein
D. Superior vena cava
E. Coronary artery
1. Item 45
Blood filtration by the kidney takes place at the:
A. vasa recta.
B. proximal tubule.
C. renal artery.
D. glomerular capillaries.
E. distal tubule.
1. Item 46
A competitive inhibitor causes:
A. Vmax to decrease and Km to remain unchanged.
B. Vmax to remain unchanged and Km to decrease.
C. Vmax to remain unchanged and Km to increase.
D. Vmax to increase and Km to remain unchanged.
E. neither Vmax nor Km to be affected.
1. Item 47
Which of the following is a characteristic of prokaryotic protein
synthesis?
14. A. Prokaryotic mRNA is monocistronic.
B. The first amino acid translated is formyl-methionine.
C. Prokaryotic transcription requires three separate RNA
polymerases.
D. The mRNA must be polyadenylated at the 3’ end.
E. Introns must be spliced out before translation can occur.
1. Item 48
What attributes of prions makes them difficult to destroy?
A. Tough outer cell wall
B. Resistance to heat and chemical treatment
C. Ability to mutate quickly
D. Resemblance to human cell surface receptors
E. Integration into the host cell genome
1. Item 49
The role of surfactant in the respiratory system is to:
A. stimulate the diaphragm.
B. increase the lipid solubility of oxygen, allowing it to diffuse
more easily into the blood.
C. dilate the bronchial tubes.
D. reduce surface tension in the alveoli.
E. trap inhaled dirt and dust particles.
1. Item 50
Which of the following contributes the most to maintenance of
the normal resting membrane potential of cells?
A. K+ leak channels
B. Na+ leak channels
C. Na+/K+ ATPase
D. Opening of voltage-gated Na+ and K+ channels
E. Establishment of a strong Na+ concentration gradient
1. Item 51
Including the ATP used for amino acid activation/tRNA
loading, approximately how many ATP equivalents are required
15. to synthesize a 200 amino acid protein?
A. 200
B. 400
C. 600
D. 800
E. 1000
1. Item 52
Which best described the process by which rod cells are
activated?
A. light strikes a depolarized rod cell → Na+ channels close →
hyperpolarization of rod stops release of an inhibitory
neurotransmitter
B. light strikes a depolarized rod cell → Na+ channels open →
hyperpolarization of rod stops release of an inhibitory
neurotransmitter
C. light strikes a rod cell at resting membrane potential →
Na+channels open → depolarization of rod leads to an action
potential
D. light strikes a rod cell at resting membrane potential →
K+channels open → hyperpolarization of rod stops release of an
inhibitory neurotransmitter
E. light strikes a depolarized rod cell → K+ channels open →
hyperpolarization of rod stops release of an inhibitory
neurotransmitter
1. Item 53
Which of the following bacterial auxotrophs should be grown in
a lactose-based medium containing arginine and threonine but
lacking histidine?
A. Arg– Lac+ Thr– His+
B. Arg– Lac– Thr+ His–
C. Arg+ Lac– Thr+ His–
D. Arg+ Lac+ Thr+ His–
E. Arg– Lac– Thr– His+
16. 1. Item 54
The area of the cerebral cortex which controls voluntary motor
function and complex reasoning is the:
A. parietal lobe.
B. frontal lobe.
C. temporal lobe.
D. occipital lobe.
E. olfactory lobe.
1. Item 55
In an operon, which of the following best describes the
promoter?
A. It is the binding site for the repressor.
B. It is a molecule that inactivates the repressor and permits
transcription.
C. It activates the repressor-inducer complex to permit
transcription.
D. It is the binding site for met-tRNAmet to initiate translation.
E. It is the binding site for RNA polymerase.
1. Item 56
In muscle cells undergoing anaerobic respiration (i.e.,
fermentation):
A. pyruvate is reduced to ethanol.
B. pyruvate is oxidized to ethanol.
C. pyruvate is reduced to lactic acid.
D. pyruvate is oxidized to lactic acid.
E. none of the above. Muscle cells cannot undergo fermentation.
1. Item 57
Spermatogenesis occurs in the:
A. vas deferens.
B. epididymis.
C. scrotum.
D. seminiferous tubules.
17. E. none of the above.
1. Item 58
Cholecystokinin functions in digestion to cause the release of:
I. trypsinogen. II. bile. III. pepsinogen.
A. II only
B. I and II only
C. I and III only
D. II and III only
E. I, II, and III
1. Item 59
Alcohol inhibits the production of antidiuretic hormone. A
person who has consumed alcohol would have:
A. increased urine output and increased urine osmolarity.
B. decreased urine output and increased urine osmolarity.
C. increased urine output and increased blood osmolarity.
D. decreased urine output and decreased blood osmolarity.
E. increased urine output and decreased blood osmolarity.
1. Item 60
Which of the following muscle fiber types uses oxidative
metabolism?
I. Type I II. Type IIa III. Type IIb
A. I only
B. I and II only
C. III only
D. II and III only
E. I, II, and III
1. Item 61
Cell surface proteins, such as receptors, begin synthesis on
cytoplasmic ribosomes, but are targeted by signal sequences
(particular amino acid sequences within the protein) to the
rough ER to complete their synthesis. Which of the following
18. statements concerning signal sequences is/are true?
I. They are hydrophobic. II. They can be found at the beginning
of the protein’s amino acid sequence. III. They are always
cleaved from the mature protein upon completion of translation.
IV. They can be found in the middle of the protein’s amino acid
sequence.
A. I and II only
B. II and III only
C. I, II, and III only
D. III only
E. I, II, and IV only
1. Item 62
Carbon dioxide is a small hydrophobic molecule that can freely
diffuse across plasma membranes. In the bloodstream, it
combines with water to form carbonic acid. Excess carbon
dioxide provides the primary drive for respiration, primarily as
dissociated carbonic acid. Low arterial PCO2 would cause all of
the following physiological changes EXCEPT:
A. decreased HCO3– reabsorption by the kidney.
B. increased HCO3– transport out of the cerebrospinal fluid.
C. faster ventilation rate.
D. decreased PCO2 in the cerebrospinal fluid.
E. increased plasma pH.
1. Item 63
Aerobic respiration in eukaryotes produces less ATP per
glucose molecule than aerobic respiration in prokaryotes. This
is because:
A. prokaryotes can produce a larger proton gradient across the
inner mitochondrial membrane, thus causing a greater driving
force for ATP synthesis.
B. eukaryotes must actively transport glucose into the
mitochondria where respiration occurs.
C. prokaryotes can generate 2.5 ATP per FADH2 molecule,
whereas eukaryotes can only generate 1.5 per FADH2.
19. D. the electrons from cytoplasmic NADH in eukaryotes are
shuttled to ubiquinone instead of NADH dehydrogenase.
E. fermentation and the tricarboxylic acid cycle can run
simultaneously in prokaryotes, generating two additional ATP
per glucose molecule.
1. Item 64
The autonomic nervous system uses several different
neurotransmitters in several different locations with several
different receptor types. Which of the following receptors binds
ACh at parasympathetic target organs?
A. Muscarinic receptors
B. Nicotinic receptors
C. α receptors
D. β receptors
E. Adrenergic receptors
1. Item 65
All of the following statements about stem cells are true
EXCEPT:
I. adult stem cells can be collected from the bone marrow and
are multipotent. II. the zygote and early cells of the embryo are
totipotent. III. embryonic stem cells are pluripotent and can
become any of the embryonic germ layers or the trophoblast.
A. I only
B. II only
C. I and III only
D. II and III only
E. I, II, and III
1. Item 66
HIV, the virus that causes AIDS, is a (+)RNA retrovirus. A
significant concern in the treatment of HIV infection with drugs
is the development of drug-resistant virus. Which of the
following is most likely to contribute to the development of
drug-resistant HIV?
20. A. Mutation of the virus after insertion into the host-cell
genome
B. Frequent random errors in transcription of the viral genome
by host-cell enzymes
C. Viral proteins folding differently in the presence of drug
than in its absence
D. Covalent modification of viral nucleic acids by the drug
E. Mutation of viral reverse transcriptase after infection of the
host cell
1. Item 67
A portion of prokaryotic mRNA has the following base
sequence: 5’ACAUCUAUGCCACGA3’. Which of the following
could result from a mutation that changes the underlined base to
A?
I. Inhibition of initiation of translation II. Truncation of the
polypeptide III. A shift in the reading frame for translation
A. I only
B. II only
C. II and III only
D. I and II only
E. I, II, and III
1. Item 68
During systole, the left ventricle of the heart pumps about 60%
of its blood out to the body. This amount is referred to as the
ejection fraction. The blood that remains in the ventricles at the
end of ejection is called the residual volume, and is typically
about 50 mL. Congestive heart failure is caused by a reduced
pumping efficiency of the left ventricle. This could result in all
of the following EXCEPT:
A. congestion of blood in the pulmonary artery.
B. residual volume less than 50 mL.
C. decreased aortic pressures and blood flow.
D. right ventricular failure.
E. pulmonary edema.
21. 1. Item 69
Polydactyly is a disorder caused by a dominant allele that
results in extra fingers. If the allele causing polydactyly is
present at a frequency of 0.2 in a certain large, isolated,
randomlymating population, what is the frequency of affected
individuals in this population?
A. 0.04
B. 0.32
C. 0.36
D. 0.64
E. 0.96
1. Item 70
Epidural block is a form of anesthesia commonly used to
prevent the pain of childbirth. It involves the injection of a
somewhat lipid-soluble anesthetic into the epidural space (a fat
filled region outside the dura mater of the spinal cord). This
successfully blocks the pain of uterine contractions during labor
without blocking the contractions themselves. This is because:
A. the somatic motor neurons innervating the uterus are not
affected by the anesthetic.
B. injection of the anesthetic occurs too low on the spinal
column to affect the uterus.
C. the anesthetic does not cross the dura mater and thus does
not affect the spinal cord.
D. the blood vessels that pick up and transport the anesthetic do
not travel to the uterus.
E. the contractions are stimulated by hormonal stimuli that are
not affected by the anesthetic.