课程名称︰普通生物学乙下
课程性质︰医学系大一必带
课程教师︰郭典翰
开课学院：医学院
开课系所︰医学系
考试日期（年月日）︰2014/05/06
考试时限（分钟）：110
是否需发放奖励金：是
（如未明确表示，则不予发放）
试题 :
Part One: Multiple-Choice Questions (2 pts each, 70 pts in total)
1. Which of the following is the best explanation for the inability of a
C 2+
specific animal cell to reduce the Ca concentration in its cytosol
compared with the extracellular fluid?
(A) low levels of protein kinase in the cell
(B) blockage of the synaptic signal
(C) insufficient ATP levels in the cytoplasm
(D) loss of transcription factors
(E) low oxygen concentration around the cell
2. An inhibitor of which of the following could be used to block the release
B of calcium from the endoplasmic reticulum?
(A) adenylyl cyclase
(B) phospholipase C
(C) tyrosine kinases
(D) serine/threonine kinases
(E) phosphodiesterase
3. Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a
C person who has recently consumed coffee would have increased levels of
(A) adenylyl cyclase.
(B) GTP.
(C) cAMP.
(D) phosphorylated proteins.
(E) activated G proteins.
4. Use this description to answer the following question.
D A major group of G protein-coupled receptors contains seven transmembrane
α helices. The amino end of the protein lies at the exterior of the plasma
membrane. Loops of amino acids connect the helices either at the exterior
face or on the cytosol face of the membrane. The loop on the cytosol side
between helices 5 and 6 is usually substantially longer than the others.
Where would you expect to find the carboxyl end?
(A) at the exterior surface
(B) between the membrane layers
(C) conected with the loop at H5 and H6
(D) at the cytosol surface
5. Use the description in Question 4 to answer the following question.
E
The coupled G protein most likely interacts with this receptor
(A) along the interior margin.
-
(B) at the -COO end.
(C) along the exterior margin.
(D) at the -NH end.
3
(E) at the loop between H5 and H6.
6. Endocrine glands that are sources of steroid hormones
E (A) are all controlled by the autonomic nervous system.
(B) secrete the steroids through ducts into the blood.
(C) operate independently of other hormonal cuing systems.
(D) store those hormones in membrane-bound vesicles.
(E) have a very short latency between steroid synthesis and steroid
release.
7. Suppose that substance X is secreted by one cell, travels via interstitial
D fluid to a neighboring cell, and produces an effect on that cell. All of
the following terms could describe this substance except
(A) prostaglandin.
(B) growth factor.
(C) neurotransmitter.
(D) pheromone.
(E) paracrine signal.
8. During mammalian labor and delivery, the contraction of uterine muscles is
E enhanced by oxytocin. This is an example of
(A) signal transduction immediately changing gene expression in its target
cells.
(B) a hormone that acts in an antagonistic way with another hormone.
(C) a negative feedback system.
(D) the key role of the anterior pituitary gland in regulating uterine
contraction.
(E) a hormone that is involved in a positive feedback loop.
9. The anterior and posterior lobes of the pituitary differ in that ＿＿.
A (A) many anterior pituitary hormones regulate other endocrine glands
whereas posterior pituitary hormones regulate nonendocrine tissues
(B) the anterior lobe of the pituitary receives neuronal impulses from
brain cells whereas the posterior lobe receives blood-borne hormones.
(C) the anterior lobe of the pituitary is nervous tissue that connects
directly to the brain whereas the posterior pituitary is derived from
non-neural tissues
(D) the posterior lobe of the pituitary operates independently of the brain
whereas the anterior lobe is directly dependent on brain activity
(E) the posterior pituitary gland synthesizes oxytocin and antidiuretic
hormone whereas the anterior lobe receives all of its hormone products
in the blood
10. In response to stress, the adrenal gland promotes the synthesis of glucose
B from noncarbohydrate substrates via the action of the steroid hormone
(A) ACTH.
(B) cortisol.
(C) epinephrine.
(D) thyroxine.
(E) glucagon.
11. Which of the following patterns of reproduction are found only among
E invertebrate animals?
(A) hermaphroditism and parthenogenesis
(B) external and internal fertilization
(C) sexual and asexual reproduction
(D) pheromonal and hormonal coordination
(E) fission and budding
12. Asexual reproduction results in greater reproductive success than does
C sexual reproduction when
(A) there is some potential for rapid overpopulation.
(B) a species is expanding into diverse geographic settings.
(C) a species is in stable and favorable environment.
(D) a species has accumulated numerous deleterious mutations.
(E) pathogens are rapidly diversifying.
13. Testosterone is synthesized primarily by the
A (A) Leydig cells.
(B) Sertoli cells.
(C) anterior pituitary gland.
(D) seminiferous tubules.
(E) hypothalamus.
14. In vertebrate animals, spermatogenesis and oogenesis differ in that
E (A) spermatogenesis is not completed until after fertilization occurs, but
oogenesis is completed by the time a girl is born.
(B) oogenesis begins at the onset of sexual maturity, whereas
spermatogenesis begins during embryonic development.
(C) oogenesis ends at menopause, whereas spermatogenesis is finished before
birth.
(D) oogenesis produces four haploid cells, whereas spermatogenesis produces
only one functional spermatozoon.
(E) cytokinesis is unequal in oogenesis, whereas it is equal in
spermatogenesis.
15. An inactivating mutation in the progesterone receptor gene would likely
E result in
(A) enlarged and hyperactive uterine endometrium.
(B) the absence of pituitary gonadotropin hormones.
(C) the absence of mammary gland development.
(D) the absence of secondary sex characteristics.
(E) the inability of the uterus to support pregnancy.
16. The formation of the fertilization membrane requires an increase in the
E availability of
(A) potassium ions.
(B) bicarbonate ions.
(C) hydrogen ions.
(D) sodium ions.
(E) calcium ions.
17. Assume that successful reproduction in a rare salamander species, wherein
D all individuals are females, relies on those females having access to sperm
from males of another species but that the resulting embryos show no signs
of a genetic contribution from the sperm. In this case, the sperm appear to
be used only for
(A) epigenesis.
(B) morphogenesis.
(C) the creation of a diploid cell.
(D) egg activation.
(E) cell differentiation.
18. The primitive streak in a bird is the functional equivalent of
C (A) polar bodies in a sea urchin.
(B) the archenteron in a frog.
(C) the lip of the blastopore in the frog.
(D) the notochord in a mammal.
(E) neural crest cells in a mammal.
19. The developmental precursors to the gonadal tissues of C. elegans uniquely
C contain
(A) proteins of maternal origin.
(B) high concentrations of potassium ions.
(C) P granules of mRNA and protein.
(D) haploid proteins.
(E) T tubules for the propagation of action potentials.
20. Reversal of left-right asymmetries in humans can arise in response to a
D genetic condition that ＿＿.
(A) leads to the absence of the thyroid gland
(B) blocks the formation of the sense of smell
(C) causes defects in myelinated neurons
(D) renders cilia immobile
(E) induces pattern formation
21. The central nervous system is lacking in animals that have
A (A) radial symmetry.
(B) a complete gut.
(C) excitable membranes.
(D) a closed circulatory system.
(E) bilateral symmetry.
22. Choose the correct match of glial cell type and function.
A (A) astrocytes–metabolize neurotransmitters and modulate synaptic
effectiveness
(B) radial glia–the source of immunoprotection against pathogens.
(C) Schwann cells–provide nutritional support to non-myelinated neurons
(D) oligodendrocytes–produce the myelin sheaths of myelinated neurons in
the peripheral nervous system
(E) microglia–produce the myelin sheaths of myelinated neurons in the
central nervous system
23. Which of the following shows a brain structure correctly paired with one of
D its primary functions?
(A) temporal lobe–visual processing
(B) occipital lobe–speech production
(C) cerebellum–language comprehension
(D) frontal lobe–decision making
(E) occipital lobe–control of skeletal muscles
24. The unconscious control of respiration and circulation are associated with
B the
(A) cerebellum.
(B) medulla oblongata.
(C) cerebrum.
(D) thalamus.
(E) corpus callosum.
25. The membrane potential that exactly offsets an ion's concentration gradient
C is called the
(A) action potential.
(B) threshold potential.
(C) equilibrium potential.
(D) graded potential.
(E) inhibitory postsynaptic potential.
26. Opening all of the sodium channels, with all other ion channels closed on
D an otherwise typical neuron should move its membrane potential to
(A) +30 mV.
(B) 0 mV.
(C) -90 mV.
(D) +62 mV.
(E) -70 mV.
27. For a neuron with an initial membrane potential at -70 mV, an increase in
E the movement of potassium ions out of that neuron's cytoplasm would result
in
(A) the replacement of potassium ions with calcium ions.
(B) the depolarization of the neuron.
(C) the neuron switching on its sodium-potassium pump to restore the
initial conditions.
(D) the replacement of potassium ions with sodium ions.
(E) the hyperpolarization of the neuron.
28. The "undershoot" phase of after-hyperpolarization is due to
E (A) slow opening of voltage-gated sodium channels.
(B) rapid opening of voltage-gated calcium channels.
(C) ions that move away from their open ion channels.
(D) slow restorative actions of the sodium-potassium ATPase.
(E) sustained opening of voltage-gated potassium channels.
29. An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more
D permeable to
(A) sodium ions.
(B) ATP.
(C) all neurotransmitter molecules.
(D) potassium ions.
(E) calcium ions.
30. Motor neurons alter skeletal muscle activities by releasing
D neurotransmitter because the motor neuron('s)
(A) signals reach the muscles via the blood.
(B) light pulses activate contraction in the muscles.
(C) is electrically coupled by gap junctions to the muscles.
(D) signals bind to receptor proteins on the muscles.
(E) is connected to the internal neural network of the muscles.
31. The perceived pitch of a sound depends on
D (A) whether or not the sound moves the incus, malleus, and stapes.
(B) which part of the oval window produces waves in the cochlear fluid.
(C) which part of the tympanic membrane is being vibrated by sound waves.
(D) which region of the basilar membrane was set in motion.
(E) the listener having had training in music.
32. Rod cells exposed to light will
A (A) hyperpolarize due to the closing of sodium channels.
(B) depolarize due to the opening of sodium channels.
(C) hyperpolarize due to the closing of potassium channels.
(D) depolarize due to the opening of potassium channels.
(E) fire one action potential for each photon received.
33. Tastes and smells are distinct kinds of environmental information in that
B (A) tastant molecules are airborne, whereas odorant molecules are dissolved
in fluids.
(B) neural projections from taste receptors reach different parts of the
brain than the neural projections from olfactory receptors.
(C) the single area of the cerebral cortex that receives smell and taste
signals can distinguish tastes and smells by the pattern of action
potentials received.
(D) odorants bind to receptor proteins, but none of the tastant stimuli
bind to receptors.
(E) distinguishing tastant molecules requires learning, whereas smell
discrimination is an innate process.
34. Compared to oxidative skeletal muscle fibers, those classified as
E glycolytic typically have
(A) a higher density of mitochondria.
(B) a darker visual appearance.
(C) a higher concentration of myoglobin.
(D) a smaller diameter.
(E) less resistance to fatigue.
35. The calcium ions released into the cytosol during excitation of skeletal
D muscle bind to
(A) tropomyosin.
(B) transverse tubules.
(C) actin.
(D) troponin.
(E) myosin.
Part Two: Match each endocrine gland or structure with the specific hormone(s)
it produces (2 pts each, 10 pts in total)
┌───┬─────────┬───────────────────────┐
│1 H │Adrenal medulla │(A) Calcitonin (J) Progesterone │
├───┼─────────┤(B) Ecdysone (K) Thyroxine │
│2 J │Corpus lutem │(C) Glucagon │
├───┼─────────┤(D) Juvenile hormone (JH) │
│3 F │Pineal gland │(E) Luteinizing hormone (LH) │
├───┼─────────┤(F) Melatonin │
│4 B │Prothoracic gland │(G) Mineralocorticoid │
├───┼─────────┤(H) Norepinephrin │
│5 A, K│Thyroid │(I) Oxytocin │
└───┴─────────┴───────────────────────┘
Part Three: Give a definition to the following terms (answer in Chinese or
English, use diagram if necessary; 4 pts each, 20 pts in total).
1. Fast block to polyspermy
The depolarization of the egg membrane that begins within 1-3 seconds after a
sperm binds to an egg membrane protein. The depolarization last about 1 minute
and prevents additional sperm from fusing with the egg during that time. The
depolarization is triggered by the opening of sodium channel that leads to an
+
influx of Na .
2. Zone of polarizing activity
A block of mesoderm located just under the ectoderm where the posterior side of
the limb bud is attached to the body. It is required for proper pattern
formation along the anterior-posterior axis of the limb.
3. Graded potential
In a neuron, a shift in the membrane potential that has an amplitude
proportional to signal strength and that decays as it spread. If the membrane
potential has shifted beyond the threshold, an action potential will be
initiated in place of graded potential.
4. Saltatory conduction
Rapid transmission of a nerve impulse along an axon, resulting from the action
potential jumping from one node of Ranvier to another, skipping the myelin-
sheathed regions of membrane.
5. Long-term potentiation
An enhanced responsiveness to an action potential by a receiving neuron. It is
mediated by increasing the expression of specific receptor for a
neurotransmitter on the post-synaptic membrane. It is thought to be involved in
learning and the formation of memories.
Part Four: Q&A (answer in Chinese or English, use diagram if necessary; 5 pts
each, 15 pts in total)
Activation of phospholipase C (PLC) by G protein-coupled receptor signaling
leads to the cleavage of PIP into DAG and IP . DAG and IP each leads to the
2 3 3
activation of a distinct signaling pathway.
Please explain how protein kinase C (PKC) integrates these two pathways.
Activation of PKC requires both DAG and the downstream event of the IP
3
pathway. IP diffuses across the cytosol and binds to the ligand-gated calcium
3
channel on the ER membrane. Calcium ion in the internal storage (ER) is then
released into cytosol. Calcium-bound PKC is then localized to cell membrane and
interact with DAG, which is associated with the membrane. The interactions with
calcium and DAG lead to a conformation change of PKC which releases the
"pseudo-substrate" domain from the kinase substrate binding site of PKC, and
thus allow PKC to access its cellular substrates.
In mammalian hormone-based sex determination, the default sex is female.
Without androgen, a genetically male (XY) individual will develop into an
anatomically normal female, with functional ovaries and female reproductive
tract. Please outline how androgen affects the sexual differentiation of gonad
and reproductive tract?
The undifferentiated gonad is bi-potential, i.e. it can develop into either an
ovary or a testis, depending on the sexual hormone present in the tissue.
Androgen drives the undifferentiated gonad toward the differentiation pathway
of testis.
However, sexual differentiation of reproductive tract is different. In the
early embryo, a set of female tract primordia (Müllerian ducts) and a set of
male tract primordia (Wolfian duct) co-exist in the body. Androgen promotes the
differentiation of Wolfian ducts into mature male reproductive tract (e.g. the
epididymis, the vas deferens, and the seminal vesicle) and the degeneration of
Müllerian ducts.
Please explain how an octopus can rapidly change its body color pattern when it
camouflages itself against the changing environment.
An octopus can sense the color pattern in its environment with its eyes. The
visual information is then processed in its "brain". The brain then sends out
commend through motor neurons to control the sizes of individual pigment cells.
In the skin of octopus, there are millions of pigment cells of different
colors. Each of these pigment cells can expand or retract depending on muscles
attached to the pigment cell, and these muscles are under neural control. The
color expressed by the skin is determined by the combinations of expanded
pigment cells. The use of neurosensory input and neuromuscular motor control
for the regulation of pigment pattern allows an octopus to change its body
color pattern rapidly.