Name:____________________________
Period___________________
Version A
AP* Biology: Endocrine and Cell Communication
Directions: Each of the questions or incomplete statements below is followed by four suggested answers or completions.
Select the one that is best in each case and enter the appropriate letter in the corresponding space on the answer sheet.
1. The term steroid describes both hormones produced
by the body and artificially produced medications
that duplicate the action for the naturally occurring
steroids. All of the following describe steroid
hormones EXCEPT?
A) They bind with receptor proteins in the plasma
membrane to trigger cellular responses.
B) They are derived from cholesterol and are lipid
soluble.
C) They serve as ligands in signal transduction
pathways.
D) They are exemplified by testosterone, estrogen
and progesterone.
2. All of the following statements about
ligand-receptor complexes are true EXCEPT
A) Most receptors exhibit ligand specificity.
B) Ligand-receptor interactions are reversible.
C) Many drugs that alter human behavior prevent
the binding of receptors’ specific ligands.
D) Ligand-receptor complexes are most often
formed in cell communication pathways in
which participating cells are in direct contact.
4.
The dashed arrows indicate the pathway taken by
chemical signals. Which of the following
statements best describes this type of cell
communication?
A) Cells communicate with distant cells using
hormones.
B) Cells communicate with each other through
direct contact.
C) Nerve cells communicate with other nerve cells
using neurotransmitter.
D) Cells use quorum sensing to communicate
density levels.
3. Cell signaling involves converting extracellular
signals to specific responses inside the target cell.
Which of the following best describes how a cell
initially responds to a signal?
A) The cell experiences a change in receptor
conformation.
B) The cell experiences an influx of ions.
C) The cell experiences an increase in protein
kinase activity.
D) The cell experiences G protein activation.
(1)Test Questions are Copyright © 1984-2002 by College Entrance Examination Board, Prenceton, NJ. All rights reserved. For face-to-fact teaching purposes, classroom teachers are permitted to reproduce the questions.
Web or Mass distribution prohibited. (2) AP ® is registered traemark of the College Entrance Examination Borard. The College Entrance Examination Board was not involved in the production of and does not endorse this
product. Permissionis granted of individual classroom teahcers to reproduce the activity sheets and illustation for their own classroom use. Any other type of reproduction of these material is strictly prohibited.
1
Version A
6. Which of the following represents the correct
ordering of the molecules that are activated by a
single molecule of epinephrine, from highest
number of molecules to lowest number of
molecules?
Quesitons 5-9
Epinephrine (also known as adrenaline or
adrenalin) is a hormone and a neurotransmitter. The
model for the action of epinephrine is shown below.
A) cAMP, protein kinase A, phosphorylase kinase,
glycogen phosphorylase
B) Glycogen phosphorylase, phosphorylasekinase,
protein kinase A, cAMP
C) cAMP, phosphorylase kinase,
glycogenphosphorylase, protein kinase A
D) Glycogen phosphorylase, cAMP, protein kinase
A, phosphorylase kinase
7. Which of the following would likely not be
observed in a person injected with epinephrine?
A)
B)
C)
D)
Decreased production of cAMP in liver cells
Inactivation of glycogen synthase
Increased glucose mobilization
Activation of G proteins
8. Which of the following best describes a benefit of
the many steps involved in a protein kinase
cascade?
A) It allows for the activation or inhibition of
many enzymes.
B) It allows for the amplification of the signal.
C) It allows for the distribution of the signal
throughout the inside of the cell.
D) All of the above.
5. Which of the following molecules act as a second
messenger in the cascade by which epinephrine
stimulates the activation of the enzyme glycogen
phosphorylase?
A)
B)
C)
D)
9. All of the following are enzymes involved in the
signal transduction pathway shown EXCEPT
Adenosine
Adenylyl cyclase
Citric acid
Cyclic AMP
A)
B)
C)
D)
2
adenyl cyclase
protein kinase A
phosphorylase kinase
epinephrine
Version A
Quesiton 10-11
G proteins are a family of proteins involved in transmitting chemical signals originating from outside a cell into the
inside of the cell. G proteins function as molecular switches.
11. Which of the following best describes the role in
which the G protein is most intimately involved in
the process shown above?
10. Investigations into the causes behind symptoms in
Alzheimer’s patients have led to the hypothesis that
the disease maybe caused by excessive activity of
IP3 second messengers in brain cells. When
comparing cell samples of Alzheimer’s patients to
those taken from the control group, which of the
following pieces of evidence would support this
hypothesis?
A)
B)
C)
D)
A) A lower number of receptor proteins in the
Alzheimer cell samples.
B) A greater volume of endoplasmic reticulum
membrane in the control group cell samples.
C) A higher concentration of calcium ions in the
cytosol of the Alzheimer cell samples.
D) A lower number of activated proteins in the
cytosol of the Alzheimer cell samples.
3
Production of the ligand molecule.
Reception of the signal.
Transduction of the signal.
Production of response to signal.
Version A
12. Blood calcium plays a role in the processes of
blood clot formation, muscle contraction and signal
conduction in neurons. Negative feedback
mechanisms regulate the release of the paired
hormones that maintain the blood calcium levels.
Which of the following statements correctly
describes this regulatory process?
A) The pituitary gland releases calcium ions when
blood calcium levels fall below the set point.
B) Calcitonin, released by the parathyroid gland,
stimulates the deposition of calcium from bones
into the blood stream when blood calcium
levels are high.
C) Thyroxine, secreted by the thyroid gland,
stimulates the release of calcium from the
parathyroid gland when blood calcium levels
fall below the set point.
D) Parathyroid glands release PTH which
stimulates the release of calcium from bones
when the blood calcium levels are lower than
the set point.
4
Version A
13.
Patients with Type 1 diabetes lack the hormone insulin. Injections of commercially produced insulin are used to
treat the symptoms of this form of diabetes. Ideally, a relatively steady level of blood glucose is maintained by the
body’s regulatory mechanisms. The data shown above was collected during an investigation comparing two insulin
therapy medicines, Insulin Glargine and NPH insulin. Which of the following conclusions is best supported by the
data?
A) NPH insulin is most efficient in
C) The rate of glucose uptake produced by
maintaining a homeostatic blood glucose
Insulin Glargine remains constant for
level during 4 to 7 hours after injection.
more than 18 hours after injection.
B) NPH and Insulin Glargine produce
D) NPH insulin stimulates the rate of insulin
similar effects on the rate of movement of
production by pancreatic beta cells.
glucose out of the blood stream.
14. In his research on cell signaling involving epinephrine, E.W. Sutherland determined glycogen phosphorylase was
activated by epinephrine. Sutherland found that in vitro, in the lab setting, epinephrine was unable to activate
phosphorylase. The reaction required live cells. Which of the following best explains why epinephrine reacted only
in live cells?
A) Epinephrine is a G-linked protein that
reacts with DNA in the signal reaction.
B) Epinephrine must be directly interacting
with glycogen phosphorylase.
C) Cell membrane proteins and molecules
inside the cell must be involved in
transmitting the signal.
D) Glycogen phosphorylase must have an
active site with an affinity for
epinephrine.
5
Version A
15.
All of the molecules described in the table above could be classified as hormones EXCEPT
A) Molecule 1
B) Molecule 2
C) Molecule 3
D) Molecule 4
16. Insulin, epinephrine, testosterone, follicle stimulating hormone, and estrogen are all capable of triggering the flow
of communication in a signal transduction pathway. Which of the following terms best describes such molecules?
A) ligands
B) receptors
C) protein hormones
D) steroid hormones
17.
A transmembrane protein is a protein that goes from one side of a membrane through to the other side of the
membrane. Which model pictured in the image above depicts a membrane protein serving as a ligand receptor in a
signal transduction pathway?
A) I only
B) II only
C) I, II and III only
D) I, II, III, and IV
6
Version A
18. Each of the following numbered processes are involved in signal transduction pathways:
I. Response
II. Amplification
III. Reception
IV. Transduction
Which of the following represents the sequence of events in a typical signal transduction pathway?
A) I, II, III, IV
B) II, III, IV, I
C) III, I, IV, II
D) III, IV, II, I
19.
T
he data shown above was collected during an experiment designed to test the hypothesis that a second messenger
mediates between receptor activation at the plasma membrane and enzyme activation in the cytoplasm. Liver tissue
was homogenated and used to make three test solutions: a whole homogenate, a fraction containing plasma
membrane, and a fraction containing cytoplasm but no plasma membrane. Which of the following would be a
reasonable conclusion based on the data collected?
A) All cells in an organism respond to the
presence of epinephrine via second
messengers present in the homogenate.
B) A soluble second messenger, produced
by hormone-activated membranes,, is
present in the solution and activates
enzymes in the cytoplasm.
C) Epinephrine is a hormone found bound in
the membrane of cells and requires a
ligand to stimulate its transduction.
D) An epinephrine signal transduction
pathway functions more efficiently at
warmer temperatures.
20.
I. Induce a rapid response
II. Result in a slow change
III. Composed of amino acid monomers
IV. Synthesized from cholesterol
V. Act as long distance chemical messengers
Which of the characteristics listed above best describe a steroid hormone?
A) I, II, and V only
B) I, II, and III only
C) II, III, and IV only
D) II, IV and V only
7
Version A
21.
Adrenalin (epinephrine) is often released in response to environmental dangers and produces the fight or flight
response. Which of the following explains why organisms with the adrenal gland arterial arrangement have a
selective advantage over those with fewer arteries connected to the adrenal gland?
A) This arrangement allows adrenalin, a
steroid hormone with receptors on blood
cells found within kidneys, to reach its
destination with little energy input.
B) This arrangement allows adrenalin, a
protein hormone, to enter the
bloodstream quickly to be distributed
throughout the body producing a rapid
release of energy.
C) This arrangement allows for adrenalin to
be converted to a second messenger
within the tissues of the kidneys to
remove dangerous chemicals.
D) This arrangement allows adrenalin to be
quickly absorbed by the kidneys and
removed from the body as urine.
8
Version A
22.
24.
At which point on the graph above are insulin
receptors on glucose carrier proteins least likely to
contain the ligand?
A) Q
B) R
C) S
D) T
Which areas in the diagram above depict the
process of transduction in the signal transduction
pathway of cell communication?
23. Which kingdoms contain organisms that employ
cell-to-cell communication?
I. Eubacteria
II. Fungi
III. Animalia
IV. Plantae
A)
B)
C)
D)
Q and R
Q and U
S and T
T and U
25. When epinephrine binds to cardiac (heart)
musclecells, it speeds their contraction. When it
binds to muscle cells of the small intestine, it
inhibits their contraction. Which of the following
best accounts for the fact that the same hormone
can have different effects on muscle cells?
A) I and II only
B) II and IV only
C) III and IV only
D) I, II, III and IV
A) Cardiac cells have more receptors for
epinephrine than do intestinal cells.
B) Epinephrine circulates to the heart first and thus
is in higher concentration around cardiac cells.
C) The two types of muscle cells have different
signal transduction pathways for epinephrine
and thus have different cellular responses.
D) Cardiac muscle is stronger than intestinal
muscle and thus has a stronger response to
epinephrine.
9
Version A
26. Which of the following best explains the difference
between a hormone and a pheromone?
Questions 29 and 30
The endocrine system is the system of glands, each
of which secretes different types of hormones
directly into the bloodstream to maintain
homeostasis. Examine the diagram below and use
the numbered glands of the human endocrine
system to answer the questions.
A) Pheromones trigger amplification of a signal
transduction pathway and hormones are local
regulators.
B) Pheromones are chemical signals between
organisms while hormones communicate
among the parts within the organism.
C) Hormones travel long within an organism and
pheromones travel short distances within an
organism.
D) Hormones are large, polar molecules and
pheromones area small, non-polar molecules.
Questions 27 and 28
Four different types of signaling mechanisms are
listed below.
I. Quorum sensing
II. Pheromone signaling
III. Endocrine signaling
IV. Paracrine signaling
27. Which signaling mechanism is exemplified by food
trail marking behaviors in insects such as ants and
termites?
A)
B)
C)
D)
I
II
III
IV
29. Which of the following indicates the gland that
secretes hormones that work together to regulate
blood glucose levels?
A)
B)
C)
D)
28. Which signaling mechanism listed above involve
chemicals being secreted into the environment?
A)
B)
C)
D)
I and II
II and III
III and IV
I, II, III, and IV
2
3
4
5
30. Which of the following is often referred to as a
“master gland ” since the hormones secreted by this
“master gland ”control a multitude of body
functions?
A)
B)
C)
D)
10
1 only
1 and 2 only
2 and 3 only
3 and 4 only
Version A
32.
31. Testosterone is a cholesterol containing hormone
produced by interstitial Leydig cells inside the
testes. Testosterone is circulated by the bloodstream
to a variety of target cells within the body including
the Sertoli cells responsible for spermatogenesis.
Which of the following statements is true regarding
testosterone?
A) Testosterone is a protein hormone involved in
paracrine signaling.
B) Testosterone is a protein hormone involved in
endocrine signaling
C) Testosterone is a steroid hormone involved in
paracrine signaling.
D) Testosterone is a steroid hormone involved in
endocrine signaling.
Which of the following statements is supported by
the information depicted in the stress hormone
feedback loop shown above?
A) A high levels of cortisol stimulates the
production of adrenocorticotropic hormone.
B) The hypothalamus will produce more
corticotropin releasing hormone in the presence
of increased levels of cortisol.
C) Increased cortisol production by the adrenal
cortex will result in decreased corticotropin
releasing hormone.
D) A decrease in the levels of cortisol will result
in an decrease in the production of
corticotropin releasing hormone.
11
AP Biology Endocrine System & Cell Communication Unit Exam
Part B Directions: These three questions require numeric answers. Calculate the correct answer for each
question, and enter your answer on the grid following each question. Examples of correct entry for the grid-in
questions are shown below. The actual questions for this exam begin on the next page.
Integer Answer
502
Integer Answer
502
5 0 2
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Decimal Answer
−4.13
−
5 0 2
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4 .
1 3
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

Fraction Answer
−2/10
−
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
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


2 /
1 0
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
1. Globally, as of 2010, an estimated
285 million people had diabetes, with
type 2 making up about 90% of the
cases. Its incidence is increasing rapidly,
and by 2030, this number is estimated to
almost double.
There are about 25.8 million people with
diabetes in the United States. The total
population of the US is 312.5 million.
Calculate the frequency of diabetes in
the US. Give your answer to three
decimal places so that it completes the
following statement:
2. The pancreas functions both as an
endocrine and an exocrine gland.
The endocrine function consists of
2 million cells called islets of
Langerhans which make up 1% of the
pancreas by weight. Sixty percent of the
islets are involved in producing insulin.
Calculate the weight of the insulin
producing cells in a pancreas having a
mass of 50.0 g. Give your answer to the
nearest one tenth of a gram.
“The frequency of diabetes in the United
States is about one in every ______
persons.”
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The Effect of Age on Testosterone Levels
Average Age
(years)
30
40
50
60
70
80
93
Total
Testesterone
(ng/dl)
617
668
608
562
524
471
376
3. Examine the data presented above. Calculate the rate of decline in testosterone between the average
age of 40 years and 50 years. Give your answer to the nearest nanogram.
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Name:____________________________
Period___________________
Version B
AP* Biology: Endocrine and Cell Communication
Directions: Each of the questions or incomplete statements below is followed by four suggested answers or completions.
Select the one that is best in each case and enter the appropriate letter in the corresponding space on the answer sheet.
Quesitons 1-5
Epinephrine (also known as adrenaline or
adrenalin) is a hormone and a neurotransmitter. The
model for the action of epinephrine is shown below.
A) It allows for the activation or inhibition of
many enzymes.
B) It allows for the amplification of the signal.
C) It allows for the distribution of the signal
throughout the inside of the cell.
D) All of the above.
2. All of the following are enzymes involved in the
signal transduction pathway shown EXCEPT
A)
B)
C)
D)
adenyl cyclase
protein kinase A
phosphorylase kinase
epinephrine
3. Which of the following represents the correct
ordering of the molecules that are activated by a
single molecule of epinephrine, from highest
number of molecules to lowest number of
molecules?
A) cAMP, protein kinase A, phosphorylase kinase,
glycogen phosphorylase
B) Glycogen phosphorylase, phosphorylasekinase,
protein kinase A, cAMP
C) cAMP, phosphorylase kinase,
glycogenphosphorylase, protein kinase A
D) Glycogen phosphorylase, cAMP, protein kinase
A, phosphorylase kinase
1. Which of the following best describes a benefit of
the many steps involved in a protein kinase
cascade?
4. Which of the following would likely not be
observed in a person injected with epinephrine?
A)
B)
C)
D)
Decreased production of cAMP in liver cells
Inactivation of glycogen synthase
Increased glucose mobilization
Activation of G proteins
(1)Test Questions are Copyright © 1984-2002 by College Entrance Examination Board, Prenceton, NJ. All rights reserved. For face-to-fact teaching purposes, classroom teachers are permitted to reproduce the questions.
Web or Mass distribution prohibited. (2) AP ® is registered traemark of the College Entrance Examination Borard. The College Entrance Examination Board was not involved in the production of and does not endorse this
product. Permissionis granted of individual classroom teahcers to reproduce the activity sheets and illustation for their own classroom use. Any other type of reproduction of these material is strictly prohibited.
1
Version B
Questions 8 and 9
5. Which of the following molecules act as a second
messenger in the cascade by which epinephrine
stimulates the activation of the enzyme glycogen
phosphorylase?
A)
B)
C)
D)
Four different types of signaling mechanisms are
listed below.
I. Quorum sensing
II. Pheromone signaling
III. Endocrine signaling
IV. Paracrine signaling
Adenosine
Adenylyl cyclase
Citric acid
Cyclic AMP
8. Which signaling mechanism is exemplified by food
trail marking behaviors in insects such as ants and
termites?
6. When epinephrine binds to cardiac (heart)
musclecells, it speeds their contraction. When it
binds to muscle cells of the small intestine, it
inhibits their contraction. Which of the following
best accounts for the fact that the same hormone
can have different effects on muscle cells?
A)
B)
C)
D)
A) Cardiac cells have more receptors for
epinephrine than do intestinal cells.
B) Epinephrine circulates to the heart first and thus
is in higher concentration around cardiac cells.
C) The two types of muscle cells have different
signal transduction pathways for epinephrine
and thus have different cellular responses.
D) Cardiac muscle is stronger than intestinal
muscle and thus has a stronger response to
epinephrine.
9. Which signaling mechanism listed above involve
chemicals being secreted into the environment?
A)
B)
C)
D)
I and II
II and III
III and IV
I, II, III, and IV
10. Testosterone is a cholesterol containing hormone
produced by interstitial Leydig cells inside the
testes. Testosterone is circulated by the bloodstream
to a variety of target cells within the body including
the Sertoli cells responsible for spermatogenesis.
Which of the following statements is true regarding
testosterone?
7.
I. Induce a rapid response
II. Result in a slow change
III. Composed of amino acid monomers
IV. Synthesized from cholesterol
V. Act as long distance chemical messengers
A) Testosterone is a protein hormone involved in
paracrine signaling.
B) Testosterone is a protein hormone involved in
endocrine signaling
C) Testosterone is a steroid hormone involved in
paracrine signaling.
D) Testosterone is a steroid hormone involved in
endocrine signaling.
Which of the characteristics listed above best
describe a steroid hormone?
A)
B)
C)
D)
I
II
III
IV
I, II, and V only
I, II, and III only
II, III, and IV only
II, IV and V only
2
Version B
Quesiton 11 and 12
G proteins are a family of proteins involved in transmitting chemical signals originating from outside a cell into the
inside of the cell. G proteins function as molecular switches.
11. Which of the following best describes the role in
which the G protein is most intimately involved in
the process shown above?
A)
B)
C)
D)
12. Investigations into the causes behind symptoms in
Alzheimer’s patients have led to the hypothesis that
the disease maybe caused by excessive activity of
IP3 second messengers in brain cells. When
comparing cell samples of Alzheimer’s patients to
those taken from the control group, which of the
following pieces of evidence would support this
hypothesis?
Production of the ligand molecule.
Reception of the signal.
Transduction of the signal.
Production of response to signal.
A) A lower number of receptor proteins in the
Alzheimer cell samples.
B) A greater volume of endoplasmic reticulum
membrane in the control group cell samples.
C) A higher concentration of calcium ions in the
cytosol of the Alzheimer cell samples.
D) A lower number of activated proteins in the
cytosol of the Alzheimer cell samples.
3
Version B
Questions 13 and 14
14. Which of the following indicates the gland that
secretes hormones that work together to regulate
blood glucose levels?
The endocrine system is the system of glands, each
of which secretes different types of hormones
directly into the bloodstream to maintain
homeostasis. Examine the diagram below and use
the numbered glands of the human endocrine
system to answer the questions.
A)
B)
C)
D)
13. Which of the following is often referred to as a
“master gland ” since the hormones secreted by this
“master gland ”control a multitude of body
functions?
A)
B)
C)
D)
1 only
1 and 2 only
2 and 3 only
3 and 4 only
4
2
3
4
5
Version B
15.
T
he data shown above was collected during an experiment designed to test the hypothesis that a second messenger
mediates between receptor activation at the plasma membrane and enzyme activation in the cytoplasm. Liver tissue
was homogenated and used to make three test solutions: a whole homogenate, a fraction containing plasma
membrane, and a fraction containing cytoplasm but no plasma membrane. Which of the following would be a
reasonable conclusion based on the data collected?
A) All cells in an organism respond to the
presence of epinephrine via second
messengers present in the homogenate.
B) A soluble second messenger, produced
by hormone-activated membranes,, is
present in the solution and activates
enzymes in the cytoplasm.
C) Epinephrine is a hormone found bound in
the membrane of cells and requires a
ligand to stimulate its transduction.
D) An epinephrine signal transduction
pathway functions more efficiently at
warmer temperatures.
5
Version B
16.
17.
The dashed arrows indicate the pathway taken by
chemical signals. Which of the following
statements best describes this type of cell
communication?
A) Cells communicate with distant cells using
hormones.
B) Cells communicate with each other through
direct contact.
C) Nerve cells communicate with other nerve cells
using neurotransmitter.
D) Cells use quorum sensing to communicate
density levels.
Which areas in the diagram above depict the
process of transduction in the signal transduction
pathway of cell communication?
A)
B)
C)
D)
Q and R
Q and U
S and T
T and U
18. Which kingdoms contain organisms that employ
cell-to-cell communication?
I. Eubacteria
II. Fungi
III. Animalia
IV. Plantae
A) I and II only
B) II and IV only
C) III and IV only
D) I, II, III and IV
6
Version B
19.
All of the molecules described in the table above could be classified as hormones EXCEPT
A) Molecule 1
B) Molecule 2
C) Molecule 3
D) Molecule 4
7
Version B
20.
Patients with Type 1 diabetes lack the hormone insulin. Injections of commercially produced insulin are used to
treat the symptoms of this form of diabetes. Ideally, a relatively steady level of blood glucose is maintained by the
body’s regulatory mechanisms. The data shown above was collected during an investigation comparing two insulin
therapy medicines, Insulin Glargine and NPH insulin. Which of the following conclusions is best supported by the
data?
C) The rate of glucose uptake produced by
A) NPH insulin is most efficient in
maintaining a homeostatic blood glucose
Insulin Glargine remains constant for
level during 4 to 7 hours after injection.
more than 18 hours after injection.
D) NPH insulin stimulates the rate of insulin
B) NPH and Insulin Glargine produce
production by pancreatic beta cells.
similar effects on the rate of movement of
glucose out of the blood stream.
21. All of the following statements about ligand-receptor complexes are true EXCEPT
A) Most receptors exhibit ligand specificity.
B) Ligand-receptor interactions are
reversible.
C) Many drugs that alter human behavior
prevent the binding of receptors’ specific
ligands.
D) Ligand-receptor complexes are most
often formed in cell communication
pathways in which participating cells are
in direct contact.
8
Version B
22.
A transmembrane protein is a protein that goes from one side of a membrane through to the other side of the
membrane. Which model pictured in the image above depicts a membrane protein serving as a ligand receptor in a
signal transduction pathway?
A) I only
B) II only
C) I, II and III only
D) I, II, III, and IV
23. Which of the following best explains the difference
between a hormone and a pheromone?
A) Pheromones trigger amplification of a signal
transduction pathway and hormones are local
regulators.
B) Pheromones are chemical signals between
organisms while hormones communicate
among the parts within the organism.
C) Hormones travel long within an organism and
pheromones travel short distances within an
organism.
D) Hormones are large, polar molecules and
pheromones area small, non-polar molecules.
9
Version B
24.
25. Cell signaling involves converting extracellular
signals to specific responses inside the target cell.
Which of the following best describes how a cell
initially responds to a signal?
A) The cell experiences a change in receptor
conformation.
B) The cell experiences an influx of ions.
C) The cell experiences an increase in protein
kinase activity.
D) The cell experiences G protein activation.
26. Blood calcium plays a role in the processes of
blood clot formation, muscle contraction and signal
conduction in neurons. Negative feedback
mechanisms regulate the release of the paired
hormones that maintain the blood calcium levels.
Which of the following statements correctly
describes this regulatory process?
Which of the following statements is supported by
the information depicted in the stress hormone
feedback loop shown above?
A) The pituitary gland releases calcium ions when
blood calcium levels fall below the set point.
B) Calcitonin, released by the parathyroid gland,
stimulates the deposition of calcium from bones
into the blood stream when blood calcium
levels are high.
C) Thyroxine, secreted by the thyroid gland,
stimulates the release of calcium from the
parathyroid gland when blood calcium levels
fall below the set point.
D) Parathyroid glands release PTH which
stimulates the release of calcium from bones
when the blood calcium levels are lower than
the set point.
A) A high levels of cortisol stimulates the
production of adrenocorticotropic hormone.
B) The hypothalamus will produce more
corticotropin releasing hormone in the presence
of increased levels of cortisol.
C) Increased cortisol production by the adrenal
cortex will result in decreased corticotropin
releasing hormone.
D) A decrease in the levels of cortisol will result
in an decrease in the production of
corticotropin releasing hormone.
10
Version B
27.
Adrenalin (epinephrine) is often released in response to environmental dangers and produces the fight or flight
response. Which of the following explains why organisms with the adrenal gland arterial arrangement have a
selective advantage over those with fewer arteries connected to the adrenal gland?
A) This arrangement allows adrenalin, a
steroid hormone with receptors on blood
cells found within kidneys, to reach its
destination with little energy input.
B) This arrangement allows adrenalin, a
protein hormone, to enter the
bloodstream quickly to be distributed
throughout the body producing a rapid
release of energy.
C) This arrangement allows for adrenalin to
be converted to a second messenger
within the tissues of the kidneys to
remove dangerous chemicals.
D) This arrangement allows adrenalin to be
quickly absorbed by the kidneys and
removed from the body as urine.
28. In his research on cell signaling involving
epinephrine, E.W. Sutherland determined glycogen
phosphorylase was activated by epinephrine.
Sutherland found that in vitro, in the lab setting,
epinephrine was unable to activate phosphorylase.
The reaction required live cells. Which of the
following best explains why epinephrine reacted
only in live cells?
29. Insulin, epinephrine, testosterone, follicle
stimulating hormone, and estrogen are all capable
of triggering the flow of communication in a signal
transduction pathway. Which of the following
terms best describes such molecules?
A)
B)
C)
D)
A) Epinephrine is a G-linked protein that reacts
with DNA in the signal reaction.
B) Epinephrine must be directly interacting with
glycogen phosphorylase.
C) Cell membrane proteins and molecules inside
the cell must be involved in transmitting the
signal.
D) Glycogen phosphorylase must have an active
site with an affinity for epinephrine.
11
ligands
receptors
protein hormones
steroid hormones
Version B
32.
30. Each of the following numbered processes are
involved in signal transduction pathways:
I. Response
II. Amplification
III. Reception
IV. Transduction
Which of the following represents the sequence of
events in a typical signal transduction pathway?
A)
B)
C)
D)
I, II, III, IV
II, III, IV, I
III, I, IV, II
III, IV, II, I
At which point on the graph above are insulin
receptors on glucose carrier proteins least likely to
contain the ligand?
31. The term steroid describes both hormones produced
by the body and artificially produced medications
that duplicate the action for the naturally occurring
steroids. All of the following describe steroid
hormones EXCEPT?
A) Q
B) R
C) S
D) T
A) They bind with receptor proteins in the plasma
membrane to trigger cellular responses.
B) They are derived from cholesterol and are lipid
soluble.
C) They serve as ligands in signal transduction
pathways.
D) They are exemplified by testosterone, estrogen
and progesterone.
12
AP Biology Endocrine System & Cell Communication Unit Exam
Part B Directions: These three questions require numeric answers. Calculate the correct answer for each
question, and enter your answer on the grid following each question. Examples of correct entry for the grid-in
questions are shown below. The actual questions for this exam begin on the next page.
Integer Answer
502
Integer Answer
502
5 0 2
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

Decimal Answer
−4.13
−
5 0 2

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
4 .
1 3

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


Fraction Answer
−2/10
−









2 /
1 0












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








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


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




1. Globally, as of 2010, an estimated
285 million people had diabetes, with
type 2 making up about 90% of the
cases. Its incidence is increasing rapidly,
and by 2030, this number is estimated to
almost double.
There are about 25.8 million people with
diabetes in the United States. The total
population of the US is 312.5 million.
Calculate the frequency of diabetes in
the US. Give your answer to three
decimal places so that it completes the
following statement:
2. The pancreas functions both as an
endocrine and an exocrine gland.
The endocrine function consists of
2 million cells called islets of
Langerhans which make up 1% of the
pancreas by weight. Sixty percent of the
islets are involved in producing insulin.
Calculate the weight of the insulin
producing cells in a pancreas having a
mass of 50.0 g. Give your answer to the
nearest one tenth of a gram.
“The frequency of diabetes in the United
States is about one in every ______
persons.”



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
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
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



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
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
The Effect of Age on Testosterone Levels
Average Age
(years)
30
40
50
60
70
80
93
Total
Testesterone
(ng/dl)
617
668
608
562
524
471
376
3. Examine the data presented above. Calculate the rate of decline in testosterone between the average
age of 40 years and 50 years. Give your answer to the nearest nanogram.

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
Name:____________________________
Period___________________
Version C
AP* Biology: Endocrine and Cell Communication
Directions: Each of the questions or incomplete statements below is followed by four suggested answers or completions.
Select the one that is best in each case and enter the appropriate letter in the corresponding space on the answer sheet.
1. In his research on cell signaling involving epinephrine, E.W. Sutherland determined glycogen phosphorylase was
activated by epinephrine. Sutherland found that in vitro, in the lab setting, epinephrine was unable to activate
phosphorylase. The reaction required live cells. Which of the following best explains why epinephrine reacted only
in live cells?
A) Epinephrine is a G-linked protein that
reacts with DNA in the signal reaction.
B) Epinephrine must be directly interacting
with glycogen phosphorylase.
C) Cell membrane proteins and molecules
inside the cell must be involved in
transmitting the signal.
D) Glycogen phosphorylase must have an
active site with an affinity for
epinephrine.
(1)Test Questions are Copyright © 1984-2002 by College Entrance Examination Board, Prenceton, NJ. All rights reserved. For face-to-fact teaching purposes, classroom teachers are permitted to reproduce the questions.
Web or Mass distribution prohibited. (2) AP ® is registered traemark of the College Entrance Examination Borard. The College Entrance Examination Board was not involved in the production of and does not endorse this
product. Permissionis granted of individual classroom teahcers to reproduce the activity sheets and illustation for their own classroom use. Any other type of reproduction of these material is strictly prohibited.
1
Version C
2.
Patients with Type 1 diabetes lack the hormone insulin. Injections of commercially produced insulin are used to
treat the symptoms of this form of diabetes. Ideally, a relatively steady level of blood glucose is maintained by the
body’s regulatory mechanisms. The data shown above was collected during an investigation comparing two insulin
therapy medicines, Insulin Glargine and NPH insulin. Which of the following conclusions is best supported by the
data?
C) The rate of glucose uptake produced by
A) NPH insulin is most efficient in
maintaining a homeostatic blood glucose
Insulin Glargine remains constant for
level during 4 to 7 hours after injection.
more than 18 hours after injection.
D) NPH insulin stimulates the rate of insulin
B) NPH and Insulin Glargine produce
production by pancreatic beta cells.
similar effects on the rate of movement of
glucose out of the blood stream.
2
Version C
Quesitons 4-8
3.
Epinephrine (also known as adrenaline or
adrenalin) is a hormone and a neurotransmitter. The
model for the action of epinephrine is shown below.
The dashed arrows indicate the pathway taken by
chemical signals. Which of the following
statements best describes this type of cell
communication?
A) Cells communicate with distant cells using
hormones.
B) Cells communicate with each other through
direct contact.
C) Nerve cells communicate with other nerve cells
using neurotransmitter.
D) Cells use quorum sensing to communicate
density levels.
4. Which of the following represents the correct
ordering of the molecules that are activated by a
single molecule of epinephrine, from highest
number of molecules to lowest number of
molecules?
A) cAMP, protein kinase A, phosphorylase kinase,
glycogen phosphorylase
B) Glycogen phosphorylase, phosphorylasekinase,
protein kinase A, cAMP
C) cAMP, phosphorylase kinase,
glycogenphosphorylase, protein kinase A
D) Glycogen phosphorylase, cAMP, protein kinase
A, phosphorylase kinase
3
Version C
8. All of the following are enzymes involved in the
signal transduction pathway shown EXCEPT
5. Which of the following molecules act as a second
messenger in the cascade by which epinephrine
stimulates the activation of the enzyme glycogen
phosphorylase?
A)
B)
C)
D)
A)
B)
C)
D)
Adenosine
Adenylyl cyclase
Citric acid
Cyclic AMP
9. All of the following statements about
ligand-receptor complexes are true EXCEPT
6. Which of the following best describes a benefit of
the many steps involved in a protein kinase
cascade?
A) Most receptors exhibit ligand specificity.
B) Ligand-receptor interactions are reversible.
C) Many drugs that alter human behavior prevent
the binding of receptors’ specific ligands.
D) Ligand-receptor complexes are most often
formed in cell communication pathways in
which participating cells are in direct contact.
A) It allows for the activation or inhibition of
many enzymes.
B) It allows for the amplification of the signal.
C) It allows for the distribution of the signal
throughout the inside of the cell.
D) All of the above.
10. Testosterone is a cholesterol containing hormone
produced by interstitial Leydig cells inside the
testes. Testosterone is circulated by the bloodstream
to a variety of target cells within the body including
the Sertoli cells responsible for spermatogenesis.
Which of the following statements is true regarding
testosterone?
7. Which of the following would likely not be
observed in a person injected with epinephrine?
A)
B)
C)
D)
adenyl cyclase
protein kinase A
phosphorylase kinase
epinephrine
Decreased production of cAMP in liver cells
Inactivation of glycogen synthase
Increased glucose mobilization
Activation of G proteins
A) Testosterone is a protein hormone involved in
paracrine signaling.
B) Testosterone is a protein hormone involved in
endocrine signaling
C) Testosterone is a steroid hormone involved in
paracrine signaling.
D) Testosterone is a steroid hormone involved in
endocrine signaling.
4
Version C
11.
A transmembrane protein is a protein that goes from one side of a membrane through to the other side of the
membrane. Which model pictured in the image above depicts a membrane protein serving as a ligand receptor in a
signal transduction pathway?
A) I only
B) II only
C) I, II and III only
D) I, II, III, and IV
12. Insulin, epinephrine, testosterone, follicle
stimulating hormone, and estrogen are all capable
of triggering the flow of communication in a signal
transduction pathway. Which of the following
terms best describes such molecules?
A)
B)
C)
D)
ligands
receptors
protein hormones
steroid hormones
5
Version C
Questions 13 and 14
15.
The endocrine system is the system of glands, each
of which secretes different types of hormones
directly into the bloodstream to maintain
homeostasis. Examine the diagram below and use
the numbered glands of the human endocrine
system to answer the questions.
Which areas in the diagram above depict the
process of transduction in the signal transduction
pathway of cell communication?
A)
B)
C)
D)
13. Which of the following is often referred to as a
“master gland ” since the hormones secreted by this
“master gland ”control a multitude of body
functions?
A)
B)
C)
D)
16. The term steroid describes both hormones produced
by the body and artificially produced medications
that duplicate the action for the naturally occurring
steroids. All of the following describe steroid
hormones EXCEPT?
1 only
1 and 2 only
2 and 3 only
3 and 4 only
A) They bind with receptor proteins in the plasma
membrane to trigger cellular responses.
B) They are derived from cholesterol and are lipid
soluble.
C) They serve as ligands in signal transduction
pathways.
D) They are exemplified by testosterone, estrogen
and progesterone.
14. Which of the following indicates the gland that
secretes hormones that work together to regulate
blood glucose levels?
A)
B)
C)
D)
Q and R
Q and U
S and T
T and U
2
3
4
5
6
Version C
17. Cell signaling involves converting extracellular
signals to specific responses inside the target cell.
Which of the following best describes how a cell
initially responds to a signal?
18.
A) The cell experiences a change in receptor
conformation.
B) The cell experiences an influx of ions.
C) The cell experiences an increase in protein
kinase activity.
D) The cell experiences G protein activation.
Which of the following statements is supported by
the information depicted in the stress hormone
feedback loop shown above?
A) A high levels of cortisol stimulates the
production of adrenocorticotropic hormone.
B) The hypothalamus will produce more
corticotropin releasing hormone in the presence
of increased levels of cortisol.
C) Increased cortisol production by the adrenal
cortex will result in decreased corticotropin
releasing hormone.
D) A decrease in the levels of cortisol will result
in an decrease in the production of
corticotropin releasing hormone.
7
Version C
Quesiton 19 and 20
G proteins are a family of proteins involved in transmitting chemical signals originating from outside a cell into the
inside of the cell. G proteins function as molecular switches.
19. Which of the following best describes the role in
which the G protein is most intimately involved in
the process shown above?
A)
B)
C)
D)
20. Investigations into the causes behind symptoms in
Alzheimer’s patients have led to the hypothesis that
the disease maybe caused by excessive activity of
IP3 second messengers in brain cells. When
comparing cell samples of Alzheimer’s patients to
those taken from the control group, which of the
following pieces of evidence would support this
hypothesis?
Production of the ligand molecule.
Reception of the signal.
Transduction of the signal.
Production of response to signal.
A) A lower number of receptor proteins in the
Alzheimer cell samples.
B) A greater volume of endoplasmic reticulum
membrane in the control group cell samples.
C) A higher concentration of calcium ions in the
cytosol of the Alzheimer cell samples.
D) A lower number of activated proteins in the
cytosol of the Alzheimer cell samples.
8
Version C
21. Each of the following numbered processes are
involved in signal transduction pathways:
I. Response
II. Amplification
III. Reception
IV. Transduction
Which of the following represents the sequence of
events in a typical signal transduction pathway?
A)
B)
C)
D)
I, II, III, IV
II, III, IV, I
III, I, IV, II
III, IV, II, I
22.
Adrenalin (epinephrine) is often released in response to environmental dangers and produces the fight or flight
response. Which of the following explains why organisms with the adrenal gland arterial arrangement have a
selective advantage over those with fewer arteries connected to the adrenal gland?
A) This arrangement allows adrenalin, a
steroid hormone with receptors on blood
cells found within kidneys, to reach its
destination with little energy input.
B) This arrangement allows adrenalin, a
protein hormone, to enter the
bloodstream quickly to be distributed
throughout the body producing a rapid
release of energy.
C) This arrangement allows for adrenalin to
be converted to a second messenger
within the tissues of the kidneys to
remove dangerous chemicals.
D) This arrangement allows adrenalin to be
quickly absorbed by the kidneys and
removed from the body as urine.
9
Version C
23.
25. Blood calcium plays a role in the processes of
blood clot formation, muscle contraction and signal
conduction in neurons. Negative feedback
mechanisms regulate the release of the paired
hormones that maintain the blood calcium levels.
Which of the following statements correctly
describes this regulatory process?
I. Induce a rapid response
II. Result in a slow change
III. Composed of amino acid monomers
IV. Synthesized from cholesterol
V. Act as long distance chemical messengers
Which of the characteristics listed above best
describe a steroid hormone?
A)
B)
C)
D)
A) The pituitary gland releases calcium ions when
blood calcium levels fall below the set point.
B) Calcitonin, released by the parathyroid gland,
stimulates the deposition of calcium from bones
into the blood stream when blood calcium
levels are high.
C) Thyroxine, secreted by the thyroid gland,
stimulates the release of calcium from the
parathyroid gland when blood calcium levels
fall below the set point.
D) Parathyroid glands release PTH which
stimulates the release of calcium from bones
when the blood calcium levels are lower than
the set point.
I, II, and V only
I, II, and III only
II, III, and IV only
II, IV and V only
24. When epinephrine binds to cardiac (heart)
musclecells, it speeds their contraction. When it
binds to muscle cells of the small intestine, it
inhibits their contraction. Which of the following
best accounts for the fact that the same hormone
can have different effects on muscle cells?
A) Cardiac cells have more receptors for
epinephrine than do intestinal cells.
B) Epinephrine circulates to the heart first and thus
is in higher concentration around cardiac cells.
C) The two types of muscle cells have different
signal transduction pathways for epinephrine
and thus have different cellular responses.
D) Cardiac muscle is stronger than intestinal
muscle and thus has a stronger response to
epinephrine.
10
Version C
26.
All of the molecules described in the table above could be classified as hormones EXCEPT
A) Molecule 1
B) Molecule 2
C) Molecule 3
D) Molecule 4
27. Which of the following best explains the difference
between a hormone and a pheromone?
28.
A) Pheromones trigger amplification of a signal
transduction pathway and hormones are local
regulators.
B) Pheromones are chemical signals between
organisms while hormones communicate
among the parts within the organism.
C) Hormones travel long within an organism and
pheromones travel short distances within an
organism.
D) Hormones are large, polar molecules and
pheromones area small, non-polar molecules.
At which point on the graph above are insulin
receptors on glucose carrier proteins least likely to
contain the ligand?
A) Q
B) R
C) S
D) T
11
Version C
Questions 29 and 30
30. Which signaling mechanism is exemplified by food
trail marking behaviors in insects such as ants and
termites?
Four different types of signaling mechanisms are
listed below.
I. Quorum sensing
II. Pheromone signaling
III. Endocrine signaling
IV. Paracrine signaling
A)
B)
C)
D)
I
II
III
IV
29. Which signaling mechanism listed above involve
chemicals being secreted into the environment?
A)
B)
C)
D)
I and II
II and III
III and IV
I, II, III, and IV
31.
T
he data shown above was collected during an experiment designed to test the hypothesis that a second messenger
mediates between receptor activation at the plasma membrane and enzyme activation in the cytoplasm. Liver tissue
was homogenated and used to make three test solutions: a whole homogenate, a fraction containing plasma
membrane, and a fraction containing cytoplasm but no plasma membrane. Which of the following would be a
reasonable conclusion based on the data collected?
A) All cells in an organism respond to the
presence of epinephrine via second
messengers present in the homogenate.
B) A soluble second messenger, produced
by hormone-activated membranes,, is
present in the solution and activates
enzymes in the cytoplasm.
C) Epinephrine is a hormone found bound in
the membrane of cells and requires a
ligand to stimulate its transduction.
D) An epinephrine signal transduction
pathway functions more efficiently at
warmer temperatures.
12
Version C
32. Which kingdoms contain organisms that employ cell-to-cell communication?
I. Eubacteria
II. Fungi
III. Animalia
IV. Plantae
A)
B)
I and II only
II and IV only
C) III and IV only
D) I, II, III and IV
13
Name:____________________________
Period___________________
Version D
AP* Biology: Endocrine and Cell Communication
Directions: Each of the questions or incomplete statements below is followed by four suggested answers or completions.
Select the one that is best in each case and enter the appropriate letter in the corresponding space on the answer sheet.
Quesiton 1 and 2
G proteins are a family of proteins involved in transmitting chemical signals originating from outside a cell into the
inside of the cell. G proteins function as molecular switches.
1. Investigations into the causes behind symptoms in
Alzheimer’s patients have led to the hypothesis that
the disease maybe caused by excessive activity of
IP3 second messengers in brain cells. When
comparing cell samples of Alzheimer’s patients to
those taken from the control group, which of the
following pieces of evidence would support this
hypothesis?
A) A lower number of receptor proteins in the
Alzheimer cell samples.
B) A greater volume of endoplasmic reticulum
membrane in the control group cell samples.
C) A higher concentration of calcium ions in the
cytosol of the Alzheimer cell samples.
D) A lower number of activated proteins in the
cytosol of the Alzheimer cell samples.
(1)Test Questions are Copyright © 1984-2002 by College Entrance Examination Board, Prenceton, NJ. All rights reserved. For face-to-fact teaching purposes, classroom teachers are permitted to reproduce the questions.
Web or Mass distribution prohibited. (2) AP ® is registered traemark of the College Entrance Examination Borard. The College Entrance Examination Board was not involved in the production of and does not endorse this
product. Permissionis granted of individual classroom teahcers to reproduce the activity sheets and illustation for their own classroom use. Any other type of reproduction of these material is strictly prohibited.
1
Version D
2. Which of the following best describes the role in
which the G protein is most intimately involved in
the process shown above?
A)
B)
C)
D)
5. In his research on cell signaling involving
epinephrine, E.W. Sutherland determined glycogen
phosphorylase was activated by epinephrine.
Sutherland found that in vitro, in the lab setting,
epinephrine was unable to activate phosphorylase.
The reaction required live cells. Which of the
following best explains why epinephrine reacted
only in live cells?
Production of the ligand molecule.
Reception of the signal.
Transduction of the signal.
Production of response to signal.
A) Epinephrine is a G-linked protein that reacts
with DNA in the signal reaction.
B) Epinephrine must be directly interacting with
glycogen phosphorylase.
C) Cell membrane proteins and molecules inside
the cell must be involved in transmitting the
signal.
D) Glycogen phosphorylase must have an active
site with an affinity for epinephrine.
3. Insulin, epinephrine, testosterone, follicle
stimulating hormone, and estrogen are all capable
of triggering the flow of communication in a signal
transduction pathway. Which of the following
terms best describes such molecules?
A)
B)
C)
D)
ligands
receptors
protein hormones
steroid hormones
6. When epinephrine binds to cardiac (heart)
musclecells, it speeds their contraction. When it
binds to muscle cells of the small intestine, it
inhibits their contraction. Which of the following
best accounts for the fact that the same hormone
can have different effects on muscle cells?
4. Each of the following numbered processes are
involved in signal transduction pathways:
I. Response
II. Amplification
III. Reception
IV. Transduction
A) Cardiac cells have more receptors for
epinephrine than do intestinal cells.
B) Epinephrine circulates to the heart first and thus
is in higher concentration around cardiac cells.
C) The two types of muscle cells have different
signal transduction pathways for epinephrine
and thus have different cellular responses.
D) Cardiac muscle is stronger than intestinal
muscle and thus has a stronger response to
epinephrine.
Which of the following represents the sequence of
events in a typical signal transduction pathway?
A)
B)
C)
D)
I, II, III, IV
II, III, IV, I
III, I, IV, II
III, IV, II, I
2
Version D
Questions 7 and 8
Quesitons 9-13
The endocrine system is the system of glands, each
of which secretes different types of hormones
directly into the bloodstream to maintain
homeostasis. Examine the diagram below and use
the numbered glands of the human endocrine
system to answer the questions.
Epinephrine (also known as adrenaline or
adrenalin) is a hormone and a neurotransmitter. The
model for the action of epinephrine is shown below.
7. Which of the following indicates the gland that
secretes hormones that work together to regulate
blood glucose levels?
A)
B)
C)
D)
9. Which of the following molecules act as a second
messenger in the cascade by which epinephrine
stimulates the activation of the enzyme glycogen
phosphorylase?
2
3
4
5
A)
B)
C)
D)
8. Which of the following is often referred to as a
“master gland ” since the hormones secreted by this
“master gland ”control a multitude of body
functions?
A)
B)
C)
D)
1 only
1 and 2 only
2 and 3 only
3 and 4 only
3
Adenosine
Adenylyl cyclase
Citric acid
Cyclic AMP
Version D
10. Which of the following would likely not be
observed in a person injected with epinephrine?
A)
B)
C)
D)
14. The term steroid describes both hormones produced
by the body and artificially produced medications
that duplicate the action for the naturally occurring
steroids. All of the following describe steroid
hormones EXCEPT?
Decreased production of cAMP in liver cells
Inactivation of glycogen synthase
Increased glucose mobilization
Activation of G proteins
A) They bind with receptor proteins in the plasma
membrane to trigger cellular responses.
B) They are derived from cholesterol and are lipid
soluble.
C) They serve as ligands in signal transduction
pathways.
D) They are exemplified by testosterone, estrogen
and progesterone.
11. Which of the following represents the correct
ordering of the molecules that are activated by a
single molecule of epinephrine, from highest
number of molecules to lowest number of
molecules?
A) cAMP, protein kinase A, phosphorylase kinase,
glycogen phosphorylase
B) Glycogen phosphorylase, phosphorylasekinase,
protein kinase A, cAMP
C) cAMP, phosphorylase kinase,
glycogenphosphorylase, protein kinase A
D) Glycogen phosphorylase, cAMP, protein kinase
A, phosphorylase kinase
15. Which kingdoms contain organisms that employ
cell-to-cell communication?
I. Eubacteria
II. Fungi
III. Animalia
IV. Plantae
A) I and II only
B) II and IV only
C) III and IV only
D) I, II, III and IV
12. All of the following are enzymes involved in the
signal transduction pathway shown EXCEPT
A)
B)
C)
D)
adenyl cyclase
protein kinase A
phosphorylase kinase
epinephrine
13. Which of the following best describes a benefit of
the many steps involved in a protein kinase
cascade?
A) It allows for the activation or inhibition of
many enzymes.
B) It allows for the amplification of the signal.
C) It allows for the distribution of the signal
throughout the inside of the cell.
D) All of the above.
4
Version D
16.
17. Which of the following best explains the difference
between a hormone and a pheromone?
A) Pheromones trigger amplification of a signal
transduction pathway and hormones are local
regulators.
B) Pheromones are chemical signals between
organisms while hormones communicate
among the parts within the organism.
C) Hormones travel long within an organism and
pheromones travel short distances within an
organism.
D) Hormones are large, polar molecules and
pheromones area small, non-polar molecules.
Which of the following statements is supported by
the information depicted in the stress hormone
feedback loop shown above?
A) A high levels of cortisol stimulates the
production of adrenocorticotropic hormone.
B) The hypothalamus will produce more
corticotropin releasing hormone in the presence
of increased levels of cortisol.
C) Increased cortisol production by the adrenal
cortex will result in decreased corticotropin
releasing hormone.
D) A decrease in the levels of cortisol will result
in an decrease in the production of
corticotropin releasing hormone.
5
Version D
18.
Patients with Type 1 diabetes lack the hormone insulin. Injections of commercially produced insulin are used to
treat the symptoms of this form of diabetes. Ideally, a relatively steady level of blood glucose is maintained by the
body’s regulatory mechanisms. The data shown above was collected during an investigation comparing two insulin
therapy medicines, Insulin Glargine and NPH insulin. Which of the following conclusions is best supported by the
data?
C) The rate of glucose uptake produced by
A) NPH insulin is most efficient in
maintaining a homeostatic blood glucose
Insulin Glargine remains constant for
level during 4 to 7 hours after injection.
more than 18 hours after injection.
D) NPH insulin stimulates the rate of insulin
B) NPH and Insulin Glargine produce
production by pancreatic beta cells.
similar effects on the rate of movement of
glucose out of the blood stream.
19.
I. Induce a rapid response
II. Result in a slow change
III. Composed of amino acid monomers
IV. Synthesized from cholesterol
V. Act as long distance chemical messengers
Which of the characteristics listed above best describe a steroid hormone?
A) I, II, and V only
B) I, II, and III only
C) II, III, and IV only
D) II, IV and V only
6
Version D
20.
Adrenalin (epinephrine) is often released in response to environmental dangers and produces the fight or flight
response. Which of the following explains why organisms with the adrenal gland arterial arrangement have a
selective advantage over those with fewer arteries connected to the adrenal gland?
A) This arrangement allows adrenalin, a
steroid hormone with receptors on blood
cells found within kidneys, to reach its
destination with little energy input.
B) This arrangement allows adrenalin, a
protein hormone, to enter the
bloodstream quickly to be distributed
throughout the body producing a rapid
release of energy.
C) This arrangement allows for adrenalin to
be converted to a second messenger
within the tissues of the kidneys to
remove dangerous chemicals.
D) This arrangement allows adrenalin to be
quickly absorbed by the kidneys and
removed from the body as urine.
7
Version D
21. Blood calcium plays a role in the processes of
blood clot formation, muscle contraction and signal
conduction in neurons. Negative feedback
mechanisms regulate the release of the paired
hormones that maintain the blood calcium levels.
Which of the following statements correctly
describes this regulatory process?
22. Cell signaling involves converting extracellular
signals to specific responses inside the target cell.
Which of the following best describes how a cell
initially responds to a signal?
A) The cell experiences a change in receptor
conformation.
B) The cell experiences an influx of ions.
C) The cell experiences an increase in protein
kinase activity.
D) The cell experiences G protein activation.
A) The pituitary gland releases calcium ions when
blood calcium levels fall below the set point.
B) Calcitonin, released by the parathyroid gland,
stimulates the deposition of calcium from bones
into the blood stream when blood calcium
levels are high.
C) Thyroxine, secreted by the thyroid gland,
stimulates the release of calcium from the
parathyroid gland when blood calcium levels
fall below the set point.
D) Parathyroid glands release PTH which
stimulates the release of calcium from bones
when the blood calcium levels are lower than
the set point.
23.
All of the molecules described in the table above could be classified as hormones EXCEPT
A) Molecule 1
B) Molecule 2
C) Molecule 3
D) Molecule 4
8
Version D
26.
Questions 24 and 25
Four different types of signaling mechanisms are
listed below.
I. Quorum sensing
II. Pheromone signaling
III. Endocrine signaling
IV. Paracrine signaling
24. Which signaling mechanism is exemplified by food
trail marking behaviors in insects such as ants and
termites?
A)
B)
C)
D)
I
II
III
IV
25. Which signaling mechanism listed above involve
chemicals being secreted into the environment?
A)
B)
C)
D)
I and II
II and III
III and IV
I, II, III, and IV
Which areas in the diagram above depict the
process of transduction in the signal transduction
pathway of cell communication?
A)
B)
C)
D)
Q and R
Q and U
S and T
T and U
27. All of the following statements about
ligand-receptor complexes are true EXCEPT
A) Most receptors exhibit ligand specificity.
B) Ligand-receptor interactions are reversible.
C) Many drugs that alter human behavior prevent
the binding of receptors’ specific ligands.
D) Ligand-receptor complexes are most often
formed in cell communication pathways in
which participating cells are in direct contact.
9
Version D
28.
At which point on the graph above are insulin
receptors on glucose carrier proteins least likely to
contain the ligand?
A) Q
B) R
C) S
D) T
29.
A transmembrane protein is a protein that goes from one side of a membrane through to the other side of the
membrane. Which model pictured in the image above depicts a membrane protein serving as a ligand receptor in a
signal transduction pathway?
A) I only
B) II only
C) I, II and III only
D) I, II, III, and IV
10
Version D
30.
T
he data shown above was collected during an experiment designed to test the hypothesis that a second messenger
mediates between receptor activation at the plasma membrane and enzyme activation in the cytoplasm. Liver tissue
was homogenated and used to make three test solutions: a whole homogenate, a fraction containing plasma
membrane, and a fraction containing cytoplasm but no plasma membrane. Which of the following would be a
reasonable conclusion based on the data collected?
A) All cells in an organism respond to the
presence of epinephrine via second
messengers present in the homogenate.
B) A soluble second messenger, produced
by hormone-activated membranes,, is
present in the solution and activates
enzymes in the cytoplasm.
C) Epinephrine is a hormone found bound in
the membrane of cells and requires a
ligand to stimulate its transduction.
D) An epinephrine signal transduction
pathway functions more efficiently at
warmer temperatures.
31. Testosterone is a cholesterol containing hormone
produced by interstitial Leydig cells inside the
testes. Testosterone is circulated by the bloodstream
to a variety of target cells within the body including
the Sertoli cells responsible for spermatogenesis.
Which of the following statements is true regarding
testosterone?
A) Testosterone is a protein hormone involved in
paracrine signaling.
B) Testosterone is a protein hormone involved in
endocrine signaling
C) Testosterone is a steroid hormone involved in
paracrine signaling.
D) Testosterone is a steroid hormone involved in
endocrine signaling.
11
Version D
32.
The dashed arrows indicate the pathway taken by
chemical signals. Which of the following
statements best describes this type of cell
communication?
A) Cells communicate with distant cells using
hormones.
B) Cells communicate with each other through
direct contact.
C) Nerve cells communicate with other nerve cells
using neurotransmitter.
D) Cells use quorum sensing to communicate
density levels.
12
AP Biology Endocrine System & Cell Communication Unit Exam
Part B Directions: These three questions require numeric answers. Calculate the correct answer for each
question, and enter your answer on the grid following each question. Examples of correct entry for the grid-in
questions are shown below. The actual questions for this exam begin on the next page.
Integer Answer
502
Integer Answer
502
5 0 2
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Decimal Answer
−4.13
−
5 0 2
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4 .
1 3
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Fraction Answer
−2/10
−
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2 /
1 0
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1. Globally, as of 2010, an estimated
285 million people had diabetes, with
type 2 making up about 90% of the
cases. Its incidence is increasing rapidly,
and by 2030, this number is estimated to
almost double.
There are about 25.8 million people with
diabetes in the United States. The total
population of the US is 312.5 million.
Calculate the frequency of diabetes in
the US. Give your answer to three
decimal places so that it completes the
following statement:
2. The pancreas functions both as an
endocrine and an exocrine gland.
The endocrine function consists of
2 million cells called islets of
Langerhans which make up 1% of the
pancreas by weight. Sixty percent of the
islets are involved in producing insulin.
Calculate the weight of the insulin
producing cells in a pancreas having a
mass of 50.0 g. Give your answer to the
nearest one tenth of a gram.
“The frequency of diabetes in the United
States is about one in every ______
persons.”
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The Effect of Age on Testosterone Levels
Average Age
(years)
30
40
50
60
70
80
93
Total
Testesterone
(ng/dl)
617
668
608
562
524
471
376
3. Examine the data presented above. Calculate the rate of decline in testosterone between the average
age of 40 years and 50 years. Give your answer to the nearest nanogram.
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