Review Questions for Form & Function 2008
1. Define diffusion and explain its relationship to the 2nd Law of Thermodynamics.
Define Active Transport and explain its relationship to both the 1st and 2nd Laws of
Thermodynamics.
2. A frog seems to defy the 2nd Law of Thermodynamics, as it lives in fresh water (low
salt) but its body encapsulates a high concentration of salt (ions such as Na+ and K+).
Explain how salt is retained in the body by a combination of active transport and
facilitated diffusion. How does this not defy the 2nd law?
3. What is the difference between an osmoconformer and an osmoregulator? Are there
any osmoconformers in saltwater? Are osmoconformers any in fresh water? Are there
osmoregulators in saltwater? Are there osmoregulators in fresh water? What are the
critical tasks faced by osmoregulators in saltwater vs. freshwater? How do they
accomplish this? What are ionregulators and ionconformers? Explain the strategies of
the following animals: hagfish, shark, toadfish, goldfish. Explain whether they are
osmoregulators or osmoconformers and whether they are ion regulators or
ionconformers.
4. Why do sharks maintain urea in their blood stream? Why doesn’t this poison their
bodies?
5. How do bony fish (Osteichthyes) in FW differ from those in SW in terms of
osmoregulation? What problems do they each face? How do they solve these problems?
6. What is the primary challenge facing terrestrial animals in terms of osmoregulation?
7. Ammonia (NH3), urea, and uric acid are all forms of nitrogenous waste. How do
these products differ in the amount of energy required to produce them? How do they
differ in their toxicity? How do they differ in terms of the concentrations at which they
can be kept in the body? Which animals use ammonia? Which use urea? Which use uric
acid? Why?
8. What are the three main processes involved in excretion in nearly all multi-cellular
animals?
9. What role does fur play in water conservation by camels? Hint: did you read page 926
of your textbook?
10. How is it that some birds and reptiles can drink seawater? Do you think that this
would be energetically expensive? Explain how a counter-current mechanism is used in
the salt gland.
11. What are the three basic functions/activities of all animal excretory systems. Where
specifically do these three basic activities occur in the mammalian nephron?
12. Fully describe the anatomy of the filter in the nephron. What is the Bowman’s
Capsule? What is the Glomerulus? What are podocytes and what is their role in
filtration? If the filter is selective, what does it select for?
13. Compare the recovery / reabsorption of the following in the (1) proximal tubule, (2)
distal tubule, (3) loop of Henle, (4) collecting duct:
H2O
Amino Acids
Urea
HCO3
Glucose
14. Propose cellular / molecular schemes for the movement of the following molecules
from the nephron lumen to interstitial fluids
- glucose across the cells of the proximal tubule
- Na+ across the cells of the thick ascending duct of the Loop of Henle
- H2O in the collecting duct
15. Describe the events that occur in the Loop of Henle and the collecting duct in
relation to the establishment of the osmotic gradient within the Loop of Henle. How does
this effect osmosis? How does this affect the movement of Na+?
16. Describe the processes that occur in the collecting duct that are responsible for the
final concentration of urine. Specifically, describe the movement of NaCl, urea, and
H2O and where and why these substances can pass.
17. Different segments of the Loop of Henle have different properties. How do the
segments differ with respect to H2O permeability and Na+ permeability and how does
this affect excretion?
18. What aspect of the kidney is most related to terrestrial adaptation? Why? What is
your bodily volume of fluid, and how much of this passes through into the kidneys every
day? How much is reabsorbed? How much fluid is used to make urine?
19. In what way is the Loop of Henle a counter current exchange mechanism?
In what way is the vasa recta a counter current exchange mechanism?
20. Explain the reabsorption of glucose and Na+ from the lumen of the nephron tubule
into the blood, using both the Na+/K+ ATPase and Na+/glucose transporter in your
answer. Use a diagram if necessary.
21. Most teleost fish excrete ammonia. Explain why the Magadi tilapia, a fish living in
highly basic water, excretes urea.
22. Assuming complete dissociation, which of the following solutions will have the
greatest osmolarity: 150 mM glucose, 80 mM NaCl, or 210 mM urea?
23. When a vampire bat feeds, it travels long distances away from its home to find a
host. After it feeds, it is often too heavy to fly. When it roosts, it doesn’t have access to
drinking water. What challenges does this pose to the bat’s kidney and how does it solve
this problem? Hint: did you read page 938 of your text book.
24. What is the composition of gastric juice? What gland(s) produce gastric juice?
Where are these glands located? What are the molecular and cellular mechanisms that
produce the components of gastric juice? What are the respective roles of Chief and
Parietal Cells? What is the role of HCl in digestion? How are the cells which produce
HCl protected from HCl?
25. Contrast mechanical digestion and enzymatic digestion. In your digestive system,
where does the majority of mechanical digestion occur? Where does the majority of
enzymatic digestion occur?
26. What are the primary functions of mouth and stomach in digestion? What is the
primary function of the small intestine? Why not deliver food directly to the small
intestine, bypassing the operations of mouth and stomach?
27. What is the function of saliva? What substances are in your saliva? What are the
roles of each of these substances? Describe the molecular and cellular processes
involved in the production and secretion of saliva? Suggest a substance present in the
saliva of a mosquito that is probably not in your saliva.
28. What are the roles of secretions from the liver and from the pancreas in digestion?
What is the role of the gall bladder?
29. Describe the types of inputs that stimulate (or suppress) secretions from the mouth,
stomach, and duodenum. To what extent does the activity at one location in the gut
influence the activity at other locations? Be specific.
30. Which hormones are released by the stomach? Which are released by the
duodenum? What specific cues cause the release of each? What and where is their
effect?
31. Explain the ways that cows, birds, teleost fish, and sharks differ in their gut
morphology. How do these animals differ from humans? What is the functional
significance of these differences?
32. Explain how the tooth morphology of mammals reflects their diets. Specifically,
discuss the differences between carnivores, herbivores, and omnivores. Explain how the
size and shape of bird bills reflects their diets. What are functional differences between
seed eaters, fish eaters, and nectar feeders?
33. Accord to your book, there are 8 “essential” amino acids. Do all animals have 8
essential amino acids? Explain the nature in which dogs, sea turtles, and cats differ in
their essential amino acids. Why is it a bad idea to feed dog food to your cat? Explain.
34. Why do humans need vitamin C and what food sources do they obtain this from? Do
all animals need vitamin C? Explain.
35. Explain the sequence of events prior to and following capturing and engulfing a meal
by a python. Why don’t pythons always maintain GI tract?
36. Describe the difference between an exocrine and an endocrine gland. Which
elements of digestion involve endocrine glands and which elements involve exocrine
glands?
37. Contrast the following chemical signals:
a) autocrine vs. paracrine vs. endocrine vs. synaptic signals
b) “simple endocrine” hormone vs. neurohormone
c) peptide hormone vs. steroid hormone
d) hormone vs. second messenger
e) hormone vs. transcription factor
38. Give an example of an autocrine, paracrine, and an endocrine process.
39. Contrast endocrine and neurosecretory cells where each stores its “materials” in
vesicles. Compare the mechanisms/processes involved in stimulating each to release its
material.
40. Describe the series of events that occur when a steroid hormone interacts with a
target cell. How does the steroid affect the activities of the cell? Which cell activities are
affected? What properties determine the type of response that a given cell will have?
41. Describe the series of events that occur when a peptide hormone interacts with a
target cell. How does the peptide affect the activities of the cell? What types of activities
are affected?
42. Why do steroid hormones require the assistance of carrier proteins in their transport
from release cell to target cell?
43. Describe the molecular/cellular response of a target cell following the binding of a
steroid to its receptor. Where is the receptor located? What happens after the steroid
binds? What two things affect the response of the cell?
44. What are G-proteins? What is their role in signal transduction? What are the
molecular properties of hormones that activate G-proteins? Describe the steps that occur
during G-protein activation and inactivation. How is cyclic AMP produced, and how is
that production related to G-proteins?
45. What is the role of glucose in energy metabolism? Describe how the availability of
glucose for energy metabolism is regulated in a homeostatic manner by glucagons and
insulin. Describe the action of cAMP and phosphorylation on the regulation of glycogen
to glucose.
46. Suggest the adaptive significance for employing such an elaborate regulatory scheme
for controlling the conversion of glycogen to glucose. If cAMP can activate a protein
simply by binding to it, why not have cAMP act directly by binding to Phosphorylase A?
How does the binding of insulin to cell receptors differ from the binding of glucagon?
Suggest a reason why it might be adaptive for insulin and glucagons to use different
receptors and different signal transduction pathways.
47. What are type 1 diabetes and type 2 diabetes? What distinguishes the two? What is
gestational diabetes? Why does the baby get too big too early when the mother has
gestational diabetes?
48. The anticancer drum tamoxifen binds to the estrogen receptor. Tamoxifen inhibits
the growth of breast tissues, but promotes growth of uterine tissues, thus reducing the risk
of breast cancer, but potentially increasing the risk of uterine cancer. Explain how the
same chemical messenger could have opposite effects in two different tissues.
49. Describe the organization of the hypothalamic and pituitary endocrine system. Of
the hormone systems we discussed in class. . . which hormones are released from which
parts of the pituitary? What hormones are released from the hypothalamus?
50. Describe the thyroid pathway, including the roles and actions of cells in the
hypothalamus, pituitary and thyroid gland. For each cell types involves ([1]
hypothalamus, [2] pituitary, [3] thyroid gland, [4] T3 target), what are the properties of
the (1) receptor system and (2) response mechanism? Describe the mechanisms of
homeostatic regulation of the thyroid pathway and the mechanisms of negative feedback
by T3/T4. What is the difference between positive and negative feedback? How does
thyroid hormone affect frog development? For TRH, TSH, and T3/T4, explain whether it
is a steroid hormone or a peptide hormone and how the hormone influences the target
cell.
51. Where is your thyroid gland located? What effect does thyroid hormone have on its
target cells?
52. Describe the effects of ADH, renin, angiotensin II, aldosterone, and atrial natriuretic
factor. In what ways are these pathways antagonistic? What happens to a rat that has had
its adrenal gland removed? Why?
53. Describe the organization of the testosterone pathway, including the hypothalamus,
pituitary, and testis. What hormones are released from each cell type and what are the
general effects on their target cells (Sertoli cells and Leydig cells)? Describe the
mechanism of homeostatic regulation of the testosterone pathway and the mechanisms of
negative feedback by testosterone. Both testosterone and FSH stimulate
spermatogenesis. Are these hormones likely to use the same cellular
mechanism?
54. Describe the anatomical components of the estrogen/progesterone pathway,
including the hypothalamus, pituitary, ovary and uterus. Describe the developmental
events in the ovary and uterus and how these events influence what hormones are being
produced during the follicular and luteal phases in the ovary, and their on the uterus.
Describe the dynamics of interactions between LH and FSH secreting cells of the
pituitary and estrogen secreting follicle cells of the uterus; describe the roles of negative
and positive feedback in regulating these processes.
55. Describe the state of a cell at rest with respect to (1) transmembrane voltage and (2)
ion distribution. What ions make important contributions to the transmembrane voltage
at rest? What factors contribute to the transmembrane ion distribution of a cell at rest?
56. Explain the transmembrane voltage in terms of (1) the Nernst Equation and (2) the
Goldman Equation.
57. What substances comprises the electric current traveling through a light bulb? What
substances comprise the electric current traveling through a nerve cell or muscle cell?
58. Describe the events that occur during an Action Potential. What factors contribute to
(1) the resting potential, (2) the rising phase, (3) the falling phase, and (4) the RP
undershoot that occurs before the cell returns to its resting state.
59. Explain the action potential in terms of (1) the Goldman Equation, (2) specific ion
permeabilities, and (3) voltage sensitive ion channels. Why is ion permeability an
important factor in governing the transmembrane voltage of a cell?
60. What are the properties of voltage sensitive Na+ and K+ channels? What is “self
inactivation”? Do both Na+ and K+ channels self inactivate?
61. Why are APs said to be “all or none”? How are APs triggered? What is the role of
“threshold” voltage in triggering of an AP? What is hyperpolarization?
62. What is the basis for the propagation of an AP down an axon? How do Schwann
cells affect the propagation of an AP down an axon?
63. If K+ concentration falls in the extracellular fluid, what would happen to the resting
membrane potential of a mammalian neuron? If Na+ concentration falls in the
extracellular fluid, what would happen to the resting membrane potential of a mammalian
neuron?
64. What happens in the dendrites, axon hillock, and axon in the propagation of an action
potential?
65. According to your book, do large, thick axons or small, skinny neurons have faster
conduction?
66. How would you have to vary each of the following properties to cause a cell’s
membrane potential to shift from -70mV to -50 mV: PK+, PNa+, PCl-, [K+]out, [K+]in,
[Na+]out, [Na+]in, [Cl-]out, [Cl-]in. In other words, how would you have to vary these
properties to cause the membrane potential to increase or to decrease?
67. Contrast electrical versus chemical synapses. Contrast direct chemical versus
indirect synapses. Contrast receptors which are neurotransmitter sensitive ion channels
with receptors that are G-protein coupled receptors. Contrast neurotransmitter sensitive
ion channels with voltage sensitive ion channels. Where does each occur in the neuron?
Where does each occur on the muscle? What properties differ between ion channels that
depolarize versus hyperpolarize the connecting cell?
68. Describe the activities of the following neurotransmitters: acetylcholine, dopamine,
serotonin, GABA. Tell whether the receptors for each involve direct synaptic
transmission or indirect synaptic transmission. For acetylcholine, dopamine, and
serotonin, explain how the transport protein (which breaks down the neurotransmitter,
thus turning it off) can be disrupted and what effects this has on the body. Explain how
Parkinson’s disease is related to dopamine. What does VX gas do?
69. Describe the pathway via which sounds are detected in mammals. What would the
consequences be of rupturing the tympanic membrane? In osteosclerosis, the stapes
becomes fused to the other middle ear bones or to the oval window. Explain how this
condition affects hearing. What are some possible reasons for hearing loss in older
people? How do mammals distinguish between pitch and volume?
70. Explain how hair cells are modified and how they send signal to the nervous system.
How does hearing in mammals differ from that in fish versus that in amphibians? How
do statocysts operate? How do the semi-circular canals (and hair cells) allow animals to
detect changes in angle and acceleration? How are hair cells used by fish to detect the
movement of water?
Multiple Choice Questions from last year’s exam
Below are the concentrations of sodium, potassium, chloride, urea, and other various ions
for natural sea water and for shark blood.
Seawater
[Na+] [K] [Cl-] [urea] [other ions]
450
10
450
0
90
total osmolality = 1000 mOsm
shark
[Na]
289
[K]
4
[Cl]
293
[urea] [other ions]
444
21
total osmolality = 1050 mOsm
1. Which of the following best describes the shark strategy?
a) The shark is an osmoregulator and an ion regulator.
b) The shark is an osmoconformer and an ion regulator.
c) The shark is an osmoregulator and an ion conformer.
d) The shark is an osmoconformer and an ion conformer.
1b. Why does the shark have high levels of urea in its blood?
a) to help match the external osmolarity of seawater.
b) to help with excretion and elimination of nitrogenous waste.
c) because it uses gills for excretion. The urea is vented at the gills.
d) because high levels of urea help keep salt from diffusing into the body.
2. At high levels, urea is toxic. Which statement best explains the presence of urea in
shark blood?
a) Sharks are adapted tolerate high levels of urea. It’s not toxic to them.
b) Sharks possess TMAO which protects proteins from urea.
c) Urea is not toxic in seawater due to the interactions between sodium and urea. .
d) Sharks vent the urea at their gills, so it is not toxic.
3. Which animals use uric acid as the final substrate of nitrogenous waste and why?
a) fish use uric acid because it dissolves well in water and is cheap to make.
b) mammals use uric acid because it is easily eliminated by the kidney.
c) sharks use uric acid because it is light and doesn’t weigh them down.
d) reptiles use uric acid because it doesn’t require much water to dilute.
Below is a drawing of the frog epithelium and the various transporters in the frog skin.
4. Which statements best explain how sodium gets in the frog body.
a) Na+ diffuses in because [Na+] is lower in the body than that in the environment.
b) Active transport causes low [Na+] in the epithelium which causes Na+ to
diffuse into the epithelium.
c) Active transport causes a low [Na+] in the frog’s body which causes Na+ to
diffuse into the body.
d) Active transport causes a high [Na+] in the epithelium which causes Na+ to
diffuse into the epithelium.
5. Tadpoles use ammonia for the final substrate of nitrogenous waste. When they
metamorphose to adults, they switch and use urea. Why do tadpoles use ammonia?
a) ammonia is less toxic than urea.
b) ammonia is more expensive to produce than urea.
c) they live in water and can easily dilute ammonia.
d) all of the above.
6. What two structures contribute to the size-selective filter in the nephron?
a) podocytes and co-transporters of proximal tubule.
b) proximal tubule and co-transporters of distal tubule
c) podocytes and gaps between endothelium cells
d) bowman’s capsule and glomerulus
Below is the Loop of Henle.
7. What are the important properties of section 2
a) water permeable, but sodium impermeable.
b) water impermeable, but sodium permeable.
c) water permeable, but sodium permeable.
d) water impermeable, but sodium impermeable.
8. What happens to the concentration of sodium (Na+) and the total amount of water in
the filtrate as it proceeds down section 2?
a) [Na+] increases and the volume of water increases
b) [Na+] decreases and the volume of water decreases
c) [Na+] decreases and the volume of water increases
d) [Na+] increases and the volume of water decreases
9. Kangaroo Rats and Beavers differ dramatically in their need to conserve water.
Which of the following statements best describes the differences in their nephrons?
a) Kangaroo Rats have short loops of Henle and beavers have long loops of Henle.
b) Kangaroo Rats have long proximal tubules and beavers have short proximal tubules.
c) Kangaroo Rats have long loops of Henle and beavers have short loops of Henle.
d) Kangaroo Rats have long distal tubules and beavers have short distal tubules.
The following two questions refer to the figure above.
10. Which of the following statements best describe the two types of synapse receptors
shown above?
A) A involves direct synaptic transmission and is very slow acting.
B involves indirect synaptic transmission and is very fast acting.
B) A involves indirect synaptic transmission and is very slow acting.
B involves direct synaptic transmission and is very fast acting.
C) A involves direct synaptic transmission and is very fast acting.
B involves indirect synaptic transmission and is very slow acting.
D) A involves indirect synaptic transmission and is very fast acting.
B involves direct synaptic transmission and is very slow acting.
E) A involves direct synaptic transmission and is very slow acting.
B involves indirect synaptic transmission and is very slow acting.
11. In figure A, which of the following statements best describes the ion channel?
A) The ion channel is voltage sensitive.
B) The ion channel is neurotransmitter sensitive.
C) The ion channel is pH sensitive.
D) All of these.
E) A and B.
Above is a picture of the action potential. The following five questions refer to this
diagram.
12. What happens in stage 3?
A) Na+ and K+ channels are open.
B) K+ channels are open and Na+ channels are closed.
C) Na+ channels are open and K+ channels are closed.
D) K+ and Na+ channels are closed.
E) Cl- channels are open.
13. What happens in stage 4?
A) Na+ and K+ channels are open.
B) K+ channels are open and Na+ channels are closed.
C) Na+ channels are open and K+ channels are closed.
D) K+ and Na+ channels are closed.
E) Cl- channels are open.
14. In what stage does self-inactivation of Na+ channels occur?
A) Stage 1
B) Stage 2
C) Stage 3
D) Stage 4
E) Stage 5
Emembrane
+
K
Na+
Cl-
 PK  [ K  ]o    PNa  [ Na  ]o    PCl  [Cl  ]i  

 25mV *ln 



 PK  [ K ]i    PNa  [ Na ]i    PCl  [Cl ]o  


In
400
50
50
at 17° C
Out
20
400
560
Above is the Goldman Equation and the concentration of ions in and outside of the
neuron.
15. What happens if the permeability of K+ is increased?
A) no change in Emembrane.
B) Emembrane increases.
C) Emembrane decreases.
16. At what point in the action potential does the permeability of K+ increase? Refer to
the diagram of the action potential for the stages.
A) Stage 1
B) Stage 2
C) Stage 3
D) Stage 4
17. What happens if the permeability of Na+ is increased?
A) no change in Emembrane.
B) Emembrane increases.
C) Emembrane decreases.
18. At what point in the action potential does the permeability of Na+ increase? Refer to
the diagram of the action potential for the stages.
A) Stage 1
B) Stage 2
C) Stage 3
D) Stage 4
19. Where in the neuron are the incoming inputs summed?
A) dendrite
B) cell body
C) axon hillock
D) axon
E) synapse
20. Which of the following increase the conduction speed of the action potential along
the axon?
A) large cell body size
B) large dendrite size
C) presence of schwann cells
D) large axon size
E) C and D
21. What happens during hyperpolarization?
A) the inside of the cells becomes more negative than the outside, therefore
Emembrane < Eresting potential
B) the inside of the cells becomes more negative than the outside, therefore
Emembrane > Eresting potential
C) the inside of the cells becomes more positive than the outside, therefore
Emembrane < Eresting potential
D) the inside of the cells becomes more positive than the outside, therefore
Emembrane > Eresting potential
22. What happens during depolarization?
A) the inside of the cells becomes more negative than the outside,
Emembrane < Eresting potential
B) the inside of the cells becomes more negative than the outside,
Emembrane > Eresting potential
C) the inside of the cells becomes more positive than the outside,
Emembrane < Eresting potential
D) the inside of the cells becomes more positive than the outside,
Emembrane > Eresting potential
Na
K+
+
Na+
K+
Cl-
Cl-
The figure above shows the relative abundances of K+, Na+, and Cl- inside and outside of
the neuron.
23. What accounts for the distribution of K+?
A) The K+/H+ pump results in high abundance of K+ outside the cell.
B) The K+/H+ pump results in high abundance of K+ inside the cell.
C) The K+/Na+ pump results in high abundance of K+ outside the cell.
D) The K+/Na+ pump results in high abundance of K+ inside the cell.
24. What accounts for the distribution of Cl-?
A) The K+/Cl- pump results in high abundance of Cl- outside the cell.
B) Negative charge from proteins drives Cl- outside the cell.
C) The high [Cl-] inside the cell favors diffusion of Cl- outside the cell.
D) The high [K+] inside the cell favors diffusion of Cl- outside the cell.
26. What is the site of GnRH synthesis and where does it have its effects?
A) GnRH is synthesized in the pituitary and has its effects on ovaries & testes.
B) GnRH is synthesized in the hypothalamus and directly effects the ovaries & testes.
C) GnRH is synthesized in the hypothalamus and directly effects the pituitary.
D) GnRH is synthesized in the hypothalamus and has its effects on the thalamus.
27. How does GnRH affect its target cell (i.e. the one it has an effect on)?
A) it alters DNA expression by immediately binding with transcription factors once it
enters the cell.
B) it alters biochemical pathways that alter the effects of other cellular processes.
C) it binds to a receptor in the cell membrane and has effects via a 2nd messenger.
D) B and C
E) all of the above
28. Which hormone(s) are secreted by the posterior pituitary?
A) oxytocin
B) thyroid stimulating hormone
C) GnRH
D) lutenizing hormone
E) B,C, and D
29. Both FSH and LH are important for spermatogenesis. Which statements best
describes their effects?
A) FSH has a direct effect on the sertoli cells, whereas LH stimulates testosterone
production in the Leydig cells, which affects the sertoli cells.
B) FSH has a direct effect on the Leydig cells, whereas LH stimulates testosterone
production in the sertoli cells, which affects the Leydig cells.
C) LH has a direct effect on the sertoli cells, whereas FSH stimulates testosterone
production in the Leydig cells, which affects the sertoli cells.
D) LH has a direct effect on the Leydig cells, whereas FSH stimulates testosterone
production in the sertoli cells, which affects the leydig cells.
30. Which statements best describe the regulation of estrogen in the early follicular
stage of the ovarian cycle?
A) FSH and LH have positive effects on estrogen secretion. Estrogen has an inhibitory
effect on GnRH secretion. This is a negative feedback.
B) FSH and LH have positive effects on estrogen secretion. Estrogen has an inhibitory
effect on GnRH secretion. This is a positive feedback.
C) FSH and LH have negative effects on estrogen secretion. Estrogen has an inhibitory
effect on GnRH secretion. This is a negative feedback.
D) FSH and LH have positive effects on estrogen secretion. Estrogen has a positive
effect on GnRH secretion. This is a positive feedback.
E) FSH and LH have positive effects on estrogen secretion. Estrogen has a positive
effect on GnRH secretion and LH secretion. This is a negative feedback.
31. Which statements best describe the regulation of estrogen in the mid-late follicular
stage of the ovarian cycle?
A) FSH and LH have positive effects on estrogen secretion. Estrogen has an inhibitory
effect on GnRH secretion. This is a negative feedback.
B) FSH and LH have positive effects on estrogen secretion. Estrogen has an inhibitory
effect on GnRH secretion. This is a positive feedback.
C) FSH and LH have negative effects on estrogen secretion. Estrogen has an inhibitory
effect on GnRH secretion. This is a negative feedback.
D) FSH and LH have positive effects on estrogen secretion. Estrogen has a positive
effect on GnRH secretion. This is a positive feedback.
E) FSH and LH have positive effects on estrogen secretion. Estrogen has a positive
effect on GnRH secretion and LH secretion. This is a negative feedback.
32. Progesterone occurs at higher levels during the luteal phase. What is the significance
of this?
A) High progresterone causes the thickening of the endometrium in the event that there is
fertilization.
B) High progresterone causes the corpus luteum to be maintained in the ovary.
C) High progesterone causes the rupture of the follicle cells and ovulation.
D) Progesterone causes a positive feedback cycle with GnRH, LH, and FSH.
E) All of the above.
33. Which of the following are likely to occur following cold stress?
A) Thyroid hormone is released which causes increased cellular metabolism.
B) TSH is released from the pituitary which causes thyroid hormone to be released from
the thyroid.
C) O2 consumption increases.
D) TRH is release from the hypothalamus and causes TSH to be released from the
pituitary.
E) All of the above.
34. Distinguish between an endocrine cell and a neurosecretory cell. Which statement is
true?
A) An endocrine cell is stimulated by a neuron.
B) A neurosecretory cell is stimulated by a neuron.
C) An endocrine cell releases neurotransmitter into the blood stream.
D) A neurosecretory cell releases neurotransmitter into the blood stream.
E) B and D
35. Type 1 diabetes destroys the Beta cells of the pancreas. What are the consequences
of this?
A) Glucagon synthesis is increased.
B) Insulin synthesis is increased.
C) The body cannot respond to increased levels of glucose in the blood.
D) The body cannot respond to decreased levels of glucose in the blood.
E) B and D
36. Which statement best describe the pathway via which glucagons activates
phorphorylase A?
A) GPCR  G protein  adenyl cyclase  cAMP  protein kinase A  phos kinase A
 phosphorylase A
B) GPCR  G protein  adenyl cyclase  protein kinase A  cAMP  phos kinase A
 phosphorylase A
C) GPCR  adenyl cyclase  G protein  protein kinase A  cAMP  phos kinase A
 phosphorylase A
D) GPCR  G protein  adenyl cyclase  cAMP  protein kinase A  protein
phosphatase phosphorylase A
E) GPCR  G protein  adenyl cyclase  cAMP  protein kinase A  phos kinase A
 glycogen synthase
37. What happens when glucose levels drop in the blood stream?
A) alpha cells in the pancreas are stimulated.
B) glucagon secretion is increased
C) beta cells in the pancreas are inhibited
D) insulin secretion is decreased
E) All of the above.
38. Which of the following statements best describes steroid hormones vs. peptide
hormones?
A) steroid hormones can freely pass through the cell membrane
B) peptide hormones are water soluble
C) steroid hormones alter gene expression by binding to transcription factors
D) peptide hormones bind to receptors on the cell membrane
E) all of the above
39. When I was young, a grouse once collided with our car right by my open window. I
was covered in a mess of mulberries. The mulberries were moist, but mostly intact.
Where did the mulberries come from?
A) the grouse’s stomach
B) the grouse’s gizzard
C) the grouse’s crop
D) the grouse’s colon
40. Why is it a bad idea to feed dog food to your cat?
A) Dog food has too much protein for cats.
B) Dog food lacks vitamin C which cats need.
C) Dog food lacks taurine which cats need.
D) Dog food is too hard for cats.
E) All of the above.
41. The salivary gland releases salt. Why does it do this?
A) This causes the release of amylase.
B) This causes the release of mucus.
C) This causes water to enter the saliva.
D) All of the above.
42. The parietal cells release HCl into the gastric gland. How do they do this? Which of
the following statements are true.
A) H+ is produced from carbonic acid and shipped out of the cell via the Na+/K+
transporter.
B) Cl- is brought into the cell via the Na+/K+ transporter and then diffuses to the lumen.
C) H+ is produced from carbonic acid and shipped out of the cell via the K+/H+
transporter.
D) Cl- is secreted into the lumen at the cost of ATP.
E) All of the above.
43. Where does most enzymatic digestion occur?
A) mouth
B) stomach
C) duodenum
D) jejunum
E) ileum
44. What would happen to a person if the colon stopped working?
A) dehydration
B) loss of salts
C) drop in body pH
D) all of the above
E) A and B
45. How are fats absorbed and transported in the intestine?
A) co-transport through microvilli cell membrane processed in ER & Golgi  released
via exocytosis  enter blood stream
B) diffuse through microvilli cell membrane processed in mitochondria  released via
endocytosis  enter lacteal
C) diffuse through microvilli cell membrane processed in mitochondria  released via
endocytosis  enter blood stream
D) diffuse through microvilli cell membrane processed in ER & Golgi  released via
exocytosis  enter lacteal
E) co-transport through microvilli cell membrane  processed in ER & Golgi 
released via exocytosis  enter lacteal
tight junction between
microvilli
C
B
A
B
C
Above is my hand drawn picture of two microvilli cells (minus the folds). I have drawn
in a co-transporter, an active transport mechanism, and a facilitated diffusion channel.
Let’s assume that an amino acid is being transported. The following two questions refer
to this drawing.
46. What does B represent?
A) amino acid
B) Na+
C) K+
D) H+
E) lipid molecule
47. What does C represent?
A) amino acid
B) Na+
C) K+
D) H+
E) lipid molecule
48. Which of the following statements is true concerning xymogens?
A) provides protection so animal doesn’t degrade itself
B) allows control of when enzymes are activated
C) allows inactive forms of enzymes to be stored away from activating agents
D) all of the above
49. How is pepsinogen activated?
A) pepsinogen is turned into pepsin in the presence of HCl
B) pepsinogen is turned into pepsin in the presence of trypsin
C) pepsinogen is turned into pepsin in the presence of mucus
D) pepsinogen is turned into pepsin in the presence of enteropeptidase
50. Which of the following statements best describe the release and action of gastrin?
A) gastrin is released into the stomach and increases secretion in the gastric gland
B) gastrin is released into the stomach and increases secretion in the duodenum
C) gastrin is released into the blood stream and increases secretion in the gastric gland
D) gastrin is released into the blood stream and increases secretion in the pancreas
E) gastrin is released into the lacteal and increases secretion in the duodenum
51. Secretin causes the pancreas to release bicarbonate in to the duodenum. What is the
consequence of this?
A) bicarbonate causes a decrease in pH
B) bicarbonate causes an increase in pH
C) bicarbonate is a peptidase and acts in enzymatic digestion
D) bicarbonate is a hormone and causes the release of trypsinogen
52. What happens in terms of the regulation of digestion when food enters the
duodenum?
A) Secretions in the duodenum are activated, and secretions in the stomach are activated.
B) Secretions in the duodenum are inhibited, but secretions in stomach are activated.
C) Secretions in the duodenum are activated, but secretions in jejunum are inhibited.
D) Secretions in the duodenum are activated, but secretions in stomach are inhibited.
53. What is the purpose of the spiral valve gut in sharks?
A) increase surface area for digestion
B) decrease surface area for digestion
C) mechanically digest food
D) allow area for salt uptake
E) B and C
54. Which elements of digestion involve exocrine glands and which involve endocrine
glands?
A) gastrin & amylase come from exocrine glands; salivary and gastric glands are
endocrine glands
B) gastrin & trypsin come from endocrine glands; salivary and gastric glands are
endocrine glands
C) gastrin & secretin come from endocrine glands; salivary and gastric glands are
exocrine glands
D) gastrin & procarboxylase come from endocrine glands; salivary and thyroid glands are
exocrine glands
E) gastrin & secretin come from endocrine glands; salivary and pituitary glands are
exocrine glands
55. What is the function of saliva in digestion?
A) protein breakdown through amylase
B) carbohydrate breakdown through amylase
C) lubricates food for easier processing
D) all of the above
E) B and C