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192 Cards in this Set
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Hormones
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They are used to communicate between different organisms.
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The secretion of hormone A causes a change in the amount of protein X in an organism. If this mechanism works by positive feedback. What could happen?
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An increase in A produces an increase in X.
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T/F
Hormones regulate cellular functions, and generally negative feedback regulates hormone levels. |
True
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What do nitric oxide and epinephrine have in common?
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They both function as neurotransmitters.
They both function as hormones. |
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Substance X is secreted by one cell, travels a short distance through interstitial fluid, and produces an effect in a cell immediately adjacent to the original secreting cell. Describe.
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nitric oxide.
neurotransmitter. prostaglandin growth factor. |
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What is the local regulator responsible for activating an enzyme that relaxes smooth muscle cells?
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nitric oxide
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Prostaglandins are local regulators whose basic structure is derived from
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fatty acids
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Which of the following examples is incorrectly paired with its class?
A) cytokines-local regulator B) estrogen-steroid hormone C) prostaglandin-peptide hormone D) ecdysone-steroid hormone E) neurotransmitter-local regulator |
C prostaglandin-peptide hormone
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What is the mode of action of aspirin and ibuprofen?
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They inhibit the synthesis of prostaglandins.
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A cell that contains proteins enabling a hormone to selectively bind to its plasma membrane is called a(n)
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target cell
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Only certain cells in the body are target cells for the steroid hormone aldosterone. Which of the following is the best explanation for why these are the only cells that respond to this hormone?
A) Only target cells are exposed to aldosterone. B) Only target cells contain receptors for aldosterone. C) Aldosterone is unable to enter nontarget cells. D) Nontarget cells destroy aldosterone before it can produce its effect. E) Nontarget cells convert aldosterone to a hormone to which they do respond. |
B Only target cells contain receptors for aldosterone
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Why is it that some body cells respond differently to the same peptide hormones?
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A target cell's response is determined by the product of a signal transduction pathway.
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Which of the following statements about hormones is incorrect?
A) They are secreted into the extracellular fluid. B) They circulate in blood or hemolymph. C) They communicate messages throughout the body. D) They travel through a dedicated pathway. E) Not all cells respond to a particular hormone. |
D They travel through a dedicated pathway
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Which of the following statements about hormones is incorrect?
A) Glands that produce them are ductless glands. B) They are produced only by organs called endocrine organs. C) Some are water soluble and some are not. D) They often maintain steady-state conditions. E) They may turn genes off or on. |
B)
They are produced only by organs called endocrine organs. |
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Which of the following does not represent a chemical signal?
A) movement of a signal from one end of a nerve to the other end of the nerve B) movement of a signal from one nerve to the next C) an immune cell releasing a cytokine D) a chemical released that affects the cell that releases it E) chemicals released into the bloodstream from nerve cells |
A)
movement of a signal from one end of a nerve to the other end of the nerve |
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Hormone X produces its effect in its target cells via the cAMP second messenger system. Which of the following will produce the greatest effect in the cell?
|
A)
a molecule of hormone X applied to the extracellular fluid surrounding the cell |
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Which of the following statements about hormones is correct?
A) Steroid and peptide hormones produce different effects but use the same biochemical mechanisms. B) Steroid and peptide hormones produce the same effects but differ in the mechanisms that produce the effects. C) Steroid hormones affect the synthesis of proteins, whereas peptide hormones affect the activity of proteins already present in the cell. D) Steroid hormones affect the activity of certain proteins within the cell, whereas peptide hormones directly affect the processing of mRNA. E) Steroid hormones affect the synthesis of proteins to be exported from the cell, whereas peptide hormones affect the synthesis of proteins that remain in the cell. |
C)
Steroid hormones affect the synthesis of proteins, whereas peptide hormones affect the activity of proteins already present in the cell. |
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Which of the following statements about hormones that promote homeostasis is incorrect?
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E)
This response feeds back to promote the release of more hormone |
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Which of the following are not part of homeostasis promotion or maintenance?
A) A stimulus causes an endocrine cell to secrete a particular hormone, which decreases the stimulus. B) A hormone acts in an antagonistic way with another hormone. C) A hormone is involved in a positive feedback loop. D) Signal transduction brings about a response in the target cell. E) Secretin promotes an increase in the pH of the duodenum. |
C)
A hormone is involved in a positive feedback loop. |
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When an individual is subject to short-term starvation, most available food is used to provide energy (metabolism) rather than building blocks (growth and repair). Which hormone would be particularly active in times of food shortage?
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glucagon
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Based on their effects, which pair below could be considered antagonistic?
A) prostaglandin F and nitric oxide B) growth hormone and ecdysone C) endocrine and exocrine glands D) hormones and target cells E) neurosecretory cells and neurotransmitters |
A)
prostaglandin F and nitric oxide |
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The endocrine system and the nervous system are structurally related. Which of the following cells best illustrates this relationship?
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C)
a neurosecretory cell in the hypothalamus |
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The hypothalamus controls the anterior pituitary by means of
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releasing hormones
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Short blood vessels connect two capillary beds lying in
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hypothalamus and anterior pituitary
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Oxytocin and ADH are produced by the __________ and stored in the _________
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hypothalamus; neurohypophysis
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If a person drinks a large amount of water in a short period of time, he or she may die from water toxicity. ADH can help prevent water retention through interaction with target cells in the
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kidney
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Which of the following statements about the hypothalamus is incorrect?
A) It functions as an endocrine gland. B) It is part of the central nervous system. C) It is subject to feedback inhibition by certain hormones. D) It secretes tropic hormones that act directly on the gonads. E) Its neurosecretory cells terminate in the posterior pituitary. |
D)
It secretes tropic hormones that act directly on the gonads |
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Which combination of hormones helps a mother to produce milk and nurse her baby?
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oxytocin and prolactin
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Many scientists think that this wide range of functions indicates which of the following?
A) Prolactin is a nonspecific hormone. B) Prolactin has a unique mechanism for eliciting its effects. C) Prolactin is an evolutionary conserved hormone. D) Prolactin is derived from two separate sources. E) Prolactin interacts with many different receptor molecules. |
C)
Prolactin is an evolutionary conserved hormone. |
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Which of the following have nontropic effects only?
A) FSH B) LH C) TSH D) MSH E) ACTH |
D)
MSH |
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The star of a recent movie was a caterpillar that never matured into an adult. It simply got larger with each molt. What is the probable reason why the caterpillar did not mature into an adult?
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increased level of juvenile hormone
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Synthetic versions of which hormones are being used as insecticides to prevent insects from maturing into reproducing adults?
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juvenile hormone
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Iodine is added to commercially-prepared table salt to help prevent deficiencies of this essential mineral. Which gland(s) require(s) iodine to function properly?
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thyroid
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Tropic hormones from the anterior pituitary directly affect the release of ?
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thyroxine
|
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Which of the following endocrine disorders is not correctly matched with the malfunctioning gland?
A) diabetes and pancreas B) giantism and pituitary C) goiter and adrenal medulla D) tetany and parathyroid E) dwarfism and pituitary |
C)
goiter and adrenal medulla |
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One reason a person might be severely overweight is due to
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an undersecretion of thyroxine.
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Which of the following statements about endocrine glands is incorrect?
A) The parathyroids regulate metabolic rate. B) The thyroid participates in blood calcium regulation. C) The pituitary participates in the regulation of the gonads. D) The adrenal medulla produces "fight-or-flight" responses. E) The pancreas helps to regulate blood sugar concentration. |
A)
The parathyroids regulate metabolic rate |
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Which of the following is an endocrine gland?
A) parathyroid gland B) salivary gland C) sweat gland D) sebaceous gland E) gallbladder |
A)
parathyroid gland |
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Which hormone exerts antagonistic action to PTH (parathyroid hormone)?
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calcitonin
|
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Which of the following glands shows both endocrine and exocrine activity?
A) pituitary B) parathyroid C) salivary D) pancreas E) adrenal |
D)
pancreas |
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All of the following are steroid hormones except
A) androgen. B) cortisol. C) estrogen. D) insulin. E) testosterone. |
D)
insulin |
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Blood samples taken from an individual who had been fasting for 24 hours would have which of the following?
A) high levels of insulin B) high levels of glucagon C) low levels of insulin D) low levels of glucagon E) both B and C |
E)
both B and C |
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What happens when beta cells of the pancreas release insulin into the blood?
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Body cells take up more glucose.
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Which of the following endocrine structures are derived from nervous tissue?
A) thymus and thyroid glands B) ovaries and the testes C) liver and the pancreas D) anterior pituitary and the adrenal cortex E) posterior pituitary and the adrenal medulla |
E)
posterior pituitary and the adrenal medulla |
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The endocrine system and the nervous system are chemically related. Which of the following substances best illustrates this relationship?
A) estrogen B) calcitonin C) norepinephrine D) calcium E) ecdysone |
C)
norepinephrine |
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Which of the following are synthesized from the amino acid tyrosine?
A) epinephrine B) catecholamines C) thyroxin D) A and B only E) A, B, and C |
E)
A, B, and C |
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Which of the following glands is controlled directly by the hypothalamus or central nervous system but not the anterior pituitary?
A) ovary B) adrenal medulla C) adrenal cortex D) testis E) thyroid |
B)
adrenal medulla |
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the adrenal cortex were removed, which group of hormones would be most affected?
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steroid
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Which of the following statements about the adrenal gland is correct?
A) During stress, TSH stimulates the adrenal cortex and medulla to secrete acetylcholine. B) During stress, the alpha cells of islets secrete insulin and simultaneously the beta cells of the islets secrete glucagon. C) During stress, ACTH stimulates the adrenal cortex, and neurons of the sympathetic nervous system stimulate the adrenal medulla. D) At all times, the anterior portion secretes ACTH, while the posterior portion secretes oxytocin. E) At all times, the adrenal gland monitors calcium levels in the blood and regulates calcium by secreting the two antagonistic hormones, epinephrine and norepinephrine. |
C)
During stress, ACTH stimulates the adrenal cortex, and neurons of the sympathetic nervous system stimulate the adrenal medulla. |
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Which of the following hormones is (are) secreted by the adrenal gland in response to stress and promote(s) the synthesis of glucose from noncarbohydrate substrates?
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glucocorticoids
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Melatonin has been found to participate in all of the following except
A) skin pigmentation. B) monitoring day length. C) reproduction. D) biological rhythms. E) calcium deposition in bone |
E)
calcium deposition in bone. |
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Which combination of gland and hormone would be linked to winter hibernation and spring reproduction in bears?
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pineal gland, melatonin
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Which of the following is a steroid hormone that triggers molting in arthropods?
A) ecdysone B) glucagon C) thyroxine D) oxytocin E) growth hormone |
A)
ecdysone |
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Which of the following is secreted by the pancreas?
A) ecdysone B) glucagon C) thyroxine D) oxytocin E) growth hormone |
B)
glucagon |
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Which of the following stimulates and maintains metabolic processes?
A) ecdysone B) glucagon C) thyroxine D) oxytocin E) growth hormone |
C)
thyroxine |
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Which of the following stimulates the contraction of uterine muscle?
A) ecdysone B) glucagon C) thyroxine D) oxytocin E) growth hormone |
D)
oxytocin |
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Which of the following is secreted by the anterior pituitary?
A) ecdysone B) glucagon C) thyroxine D) oxytocin E) growth hormone |
E)
growth hormone |
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Which of the following endocrine structures is (are) not controlled by a tropic hormone from the anterior pituitary?
A) pancreatic islet cells B) thyroid gland C) adrenal cortex D) ovaries E) testes |
A)
pancreatic islet cells |
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Testosterone is an example of
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an androgen
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Estradiol is an example of
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an estrogen.
|
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Which of the following is secreted by the pineal gland?
A) androgens B) estrogens C) progestins D) catecholamines E) melatonin |
E)
melatonin |
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Epinephrine is an example of
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a catecholamine.
|
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Which of the following is not an accurate statement?
A) Hormones are chemical messengers that travel to target cells through the circulatory system. B) Hormones often regulate homeostasis through antagonistic functions. C) Hormones of the same chemical class usually have the same function. D) Hormones are secreted by specialized cells usually located in endocrine glands. E) Hormones are often regulated through feedback loops |
C)
Hormones of the same chemical class usually have the same function. |
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A distinctive feature of the mechanism of action of thyroid hormones and steroid hormones is that
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these hormones bind to receptors inside cells
|
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Growth factors are local regulators that
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are proteins that bind to cell-surface receptors and stimulate growth and development of target cells.
|
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Which of the following hormones is incorrectly paired with its action?
A) Oxytocin stimulates uterine contractions during childbirth B) Thyroxine stimulates metabolic processes C) Insulin stimulates glycogen breakdown in the liver D) ACTH stimulates the release of glucocorticoids by the adrenal cortex E) Melatonin affects biological rhythms, seasonal reproduction |
C)
Insulin stimulates glycogen breakdown in the liver |
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An example of antagonistic hormones controlling homeostasis is
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insulin and glucagon in glucose metabolism
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Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal?
A) a disproportionate production of T3 to T4 B) hyposecretion of TSH C) hypersecretion of TSH D) hypersecretion of MSH E) a decrease in the thyroid secretion of calcitonin |
B)
hyposecretion of TSH |
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The main target organs for tropic hormones are
|
C)
endocrine glands |
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The relationship between the insect hormones ecdysone and PTTH
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is an example of the interaction between the endocrine and nervous systems.
|
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Which of the following is a sensation and not a perception?
A) seeing the colors in a rainbow B) a nerve impulse induced by sugar stimulating sweet receptors on the tongue C) the smell of natural gas escaping from an open burner on a gas stove D) the unique taste of french fries with cheese E) the sound of a fire-truck siren as it passes by your car |
B)
a nerve impulse induced by sugar stimulating sweet receptors on the tongue |
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Why are we able to differentiate tastes and smells?
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The action potentials initiated by taste receptors are transmitted to a separate region of the brain than those initiated by receptors for smell.
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If a stimulus is to be perceived by the nervous system, which part of the sensory pathway must occur first?
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reception
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What is the correct sequence of events that would lead to a person hearing a sound?
1. transmission 2. transduction 3. integration 4. amplification |
C)
2, 4, 1, 3 |
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Immediately after putting on a shirt, your skin feels itchy. However, the itching stops after a few minutes and you are unaware that you are wearing a shirt. Why?
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Sensory adaptation has occurred.
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Which of the following is a good example of sensory adaptation?
A) olfactory receptors ceasing to produce receptor potentials when triggered by the smell of the second batch of cookies you are baking B) hair cells in the organ of Corti not responding to high-pitched sounds after you have worked on the same construction job for 30 years C) cones in the human eye failing to respond to light in the infrared range D) hair cells in the utricle and saccule responding to a change in orientation when you bend your neck forward after you have been reading a book E) rods in the human eye responding to mechanical stimulation from a blow to the back of the head so that a flash of light is perceived |
A)
olfactory receptors ceasing to produce receptor potentials when triggered by the smell of the second batch of cookies you are baking |
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Why does your arm feel cold when you reach inside the refrigerator to get a container of milk?
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Thermoreceptors send signals to the posterior hypothalamus
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Which of the following receptors is incorrectly paired with the type of energy it transduces?
A) mechanoreceptors sound B) electromagnetic receptors magnetism C) chemoreceptors solute concentrations D) thermoreceptors heat E) pain receptors electricity |
E)
pain receptors electricity |
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What do hearing, touch, and a full stomach have in common?
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Electrical energy is transduced to form an action potential.
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Why is it less useful to think of behavior as a linear series of sensing, analyzing, and acting than as a continuous cyclical process?
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When an organism is acting it may also be sensing and analyzing another stimulus
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Which of the following is controlled by the magnitude of a receptor potential?
A) the rate of production of an action potential B) the rate of reaction of the brain C) the rate of response to a sensory neuron D) perception E) adaptation |
A)
the rate of production of an action potential |
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A given photon of light may trigger an action potential with thousands of times more energy. How is this signal strength magnified?
|
by an enzymatic reaction
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What is a muscle spindle?
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groups of dendrite-encircled muscle fibers
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"Hot" peppers taste this way because of capsaicin. It is said to taste hot because
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it activates the same receptors as something heated
|
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What impact would a nonfunctioning statocyst have on an earthworm? The earthworm would not be able to
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orient with respect to gravity
|
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The pathway leading to the perception of sound by mammals begins with the
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hair cells of the organ of Corti, which rests on the basilar membrane, coming in contact with the tectorial membrane
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The perceived pitch of a sound depends on
|
the region of the basilar membrane where the signal originated
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Which of the following is an attachment site between sensory hairs that open ion channels when the hairs bend?
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tip links
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Which of the following contains mechanoreceptors that react to low frequency waves in much the same manner as our inner ear?
A) our sense of taste B) pain receptors C) receptors for light touch D) lateral line systems E) eye cups of Planaria |
D)
lateral line systems |
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What are sensillae?
|
insect taste receptors found on feet and mouthparts
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What portion of the brain has neurons that receive action potentials from chemoreceptor cells in the nose?
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olfactory bulb
|
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Which of the following is perceived as umami?
A) the smooth and lush taste of cheesecake B) a rich chocolate taste C) a savory complex cheese D) spoiled milk E) saltwater |
C)
a savory complex cheese |
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What is the relationship between taste cells and number of expressed receptor types?
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1 : 1
|
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Which of the major senses responds by means of a very large gene family?
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smell
|
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It is very difficult to sneak up to a grasshopper and catch it. Why?
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They have compound eyes with multiple ommatidia.
|
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Which of the following is a correct statement about the cells of the human retina?
A) Cone cells can detect color, but rod cells cannot. B) Cone cells are more sensitive to light than rod cells are. C) Cone cells, but not rod cells, have a visual pigment. D) Rod cells are most highly concentrated in the center of the retina. E) Rod cells require higher illumination for stimulation than do cone cells. |
A)
Cone cells can detect color, but rod cells cannot |
|
The axons of rods and cones synapse with
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bipolar cells
|
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Which of the following structures is the last one that sensory information would encounter during visual processing?
A) ganglion cells B) bipolar cells C) primary visual cortex D) optic chiasma E) lateral geniculate nuclei |
C)
primary visual cortex |
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If a baseball player is hit in the back of the head, which part of his brain would be the most likely injured?
|
the primary visual cortex
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What structural feature(s) contribute(s) most to the diverse adaptations for animal movement?
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skeletal system and muscular system
|
|
Skeletal fibers may be classified as either oxidative or glycolytic. Which of the following muscles would be called glycolytic?
A) those with a high concentration of myoglobin B) those with a large number of mitochondria C) the dark muscle meat of poultry D) those with the smallest diameters E) the ones most easily fatigued |
E)
the ones most easily fatigued |
|
Duchenne muscular dystrophy is a sex-linked condition in humans that results from abnormal dystrophin protein. The condition results in progressive weakening and atrophy of muscles, usually beginning with the legs. This is most consistent with which of the following?
A) an abnormality of actin protein distribution B) a structural abnormality of the sarcomere C) a disturbance of smooth muscle D) an abnormality of calcium channels E) an enzymatic abnormality |
B)
a structural abnormality of the sarcomere |
|
When an organism dies, its muscles remain in a contracted state termed "rigor mortis" for a brief period of time. Which of the following most directly contributes to this phenomenon? There is no
A) ATP to move cross-bridges. B) ATP to break bonds between the thick and thin filaments. C) calcium to bind to troponin. D) oxygen supplied to muscle. E) glycogen remaining in the muscles. |
B)
ATP to break bonds between the thick and thin filaments. |
|
Which of the following does not form part of the thin filaments of a muscle cell?
A) actin B) troponin C) tropomyosin D) myosin E) calcium-binding site |
D)
myosin |
|
What is the role of calcium in muscle contractions?
|
bind to the troponin complex, which leads to the exposure of the myosin-binding sites
|
|
Muscle cells are stimulated by neurotransmitters released from the synaptic terminal of
|
motor neuron axons
|
|
Which function associated with muscle would be most directly affected by low levels of calcium?
|
muscle contraction
|
|
Which of the following is the correct sequence that occurs during the excitation and contraction of a muscle cell?
1. Tropomyosin shifts and unblocks the cross-bridge binding sites. 2. Calcium is released and binds to the troponin complex. 3. Transverse tubules depolarize the sarcoplasmic reticulum. 4. The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP. 5. An action potential in a motor neuron causes the axon to release acetylcholine, which depolarizes the muscle cell membrane. A) 1, 2, 3, 4, 5 B) 2, 1, 3, 5, 4 C) 2, 3, 4, 1, 5 D) 5, 3, 1, 2, 4 E) 5, 3, 2, 1, 4 |
E)
5, 3, 2, 1, 4 |
|
Which of the following could you find in the lumen of a transverse tubule?
A) extracellular fluid B) cytoplasm C) actin D) myosin E) sarcomeres |
A)
extracellular fluid |
|
A sustained muscle contraction due to a lack of relaxation between successive stimuli is called
|
tetanus.
|
|
Which of the following are shared by skeletal, cardiac, and smooth muscle?
A) A bands and I bands B) transverse tubules C) gap junctions D) motor units E) thick and thin filaments |
E)
thick and thin filaments |
|
What are animals with hydrostatic skeletons able to do that animals with exoskeletons or internal skeletons cannot do?
|
elongate
|
|
Which of the following could be associated with peristalsis?
A) hydrostatic skeletons and smooth muscle B) hydrostatic skeletons and movement in earthworms C) smooth muscle and contractions along the human digestive tract causing movement of the contents within D) A and C only E) A, B, and C |
E)
A, B, and C |
|
Which of the following would be expected to expend the greatest amount of energy for locomotion per unit mass?
A) a tadpole B) a bony fish C) a terrestrial reptile D) a robin E) a whale |
D)
a robin |
|
Which of the following sensory receptors is incorrectly paired with its category?
A) hair cell mechanoreceptor B) muscle spindle mechanoreceptor C) taste receptor chemoreceptor D) Rod electromagnetic receptor E) olfactory receptor electromagnetic receptor |
E)
olfactory receptor electromagnetic receptor |
|
Some sharks close their eyes just before they bite. Although they cannot see their prey, their bites are on target. Researchers have noted that sharks often misdirect their bites at metal objects, and that sharks can find batteries buried under the sand of an aquarium. This evidence suggests that sharks keep track of their prey during the split second before they bite in the same way that a
|
platypus locates its prey in a muddy river
|
|
The transduction of sound waves into action potentials takes place
|
when hair cells are bent against the tectorial membrane, causing them to depolarize and release neurotransmitter that stimulates sensory neurons
|
|
Which of the following is an incorrect statement about the vertebrate eye?
A) The vitreous humor regulates the amount of light entering the pupil. B) The transparent cornea is an extension of the sclera. C) The fovea is the center of the visual field and contains only cones. D) The ciliary muscle functions in accommodation. E) The retina lies just inside the choroid and contains the photoreceptor cells. |
A)
The vitreous humor regulates the amount of light entering the pupil |
|
When light strikes the rhodopsin in a rod, retinal isomerizes, initiating a signal transduction pathway that
|
hyperpolarizes the rod, reducing its release of glutamate, which excites some bipolar cells and inhibits others.
|
|
Both the eye and the respiratory tract are protected against infections by
|
the secretion of lysozyme onto their surface
|
|
How do people contract salmonella poisoning?
|
The microbe can survive the acidic environment of the stomach and resist lysosomal degradation in macrophages
|
|
Which statement about the complement system is true?
A) These proteins are involved in innate immunity and not acquired immunity. B) These proteins are secreted by cytotoxic T cells and other CD8 cells. C) This group of proteins includes interferons and interleukins. D) These proteins are one group of antimicrobial proteins acting together in cascade fashion. E) These proteins act individually to attack and lyse microbes |
D)
These proteins are one group of antimicrobial proteins acting together in cascade fashion. |
|
Which action below is affected by an antihistamine?
A) blood vessel dilation B) phagocytosis of antigens C) MHC presentation by macrophages D) the secondary immune response E) clonal selection by antigens |
A)
blood vessel dilation |
|
Which cells and which signaling molecules are responsible for initiating an inflammatory response?
|
D)
mast cells: histamines |
|
Inflammatory responses may include which of the following?
A) clotting proteins migrating away from the site of infection B) increased activity of phagocytes in an inflamed area C) reduced permeability of blood vessels to conserve plasma D) release of substances to decrease the blood supply to an inflamed area E) inhibiting the release of white blood cells from bone marrow |
B)
increased activity of phagocytes in an inflamed area |
|
A bacterium entering the body through a small cut in the skin will do which of the following?
A) inactivate the erythrocytes B) stimulate apoptosis of nearby body cells C) stimulate release of interferons D) stimulate natural killer cell activity E) activate a group of proteins called complement |
E)
activate a group of proteins called complement |
|
An invertebrate, such as an insect, has innate immunity that can be nonspecific about which pathogens are prevented from harming its metabolism. Which of the following is most likely to function this way in the insect's intestine?
A) complement B) lysozyme C) mucus D) neutrophils E) dendritic cells |
B)
lysozyme |
|
In some insects, such as Drosophila, fungal cell wall elements can activate the protein Toll. What is Toll's function?
|
acts as a receptor that, when activated, signals synthesis of antimicrobial peptides
|
|
Mammals have Toll-like receptors (TLRs) that act in a manner similar to those of insects. While not specific to a particular pathogen, a TLR can recognize a kind of macromolecule that is absent from vertebrates but present in/on certain groups of pathogens. Which of the following is most likely to be recognized by a particular TLR that defends against some viruses?
A) lipopolysaccharides B) double-stranded DNA C) double-stranded RNA D) glycoproteins E) phospholipids |
C)
double-stranded RNA |
|
Histamines trigger dilation of nearby blood vessels, and increase in their permeability. Which of the signs of inflammation are therefore associated with histamine release?
|
redness, heat, and swelling
|
|
A bacterium has elements on its surface that are resistant to lysozyme. If an individual is infected with this bacterium, what is a probable consequence?
|
B)
successful reproduction of the bacterium and continued disease |
|
What are antigens?
|
foreign molecules that trigger the generation of antibodies
|
|
If a newborn were accidentally given a drug that destroyed the thymus, what would most likely happen?
|
His T cells would not mature and differentiate appropriately.
|
|
Clonal selection implies that
|
antigens increase mitosis in specific lymphocytes
|
|
Clonal selection is an explanation for how
|
an antigen can provoke production of high levels of specific antibodies
|
|
A person exposed to a new cold virus would not feel better for one to two weeks because
|
no memory cells can be called upon, so adequate response is slow
|
|
Which of the following cell types are responsible for initiating a secondary immune response?
|
memory cells
|
|
Which of the following differentiates T cells and B cells?
A) T cells but not B cells are stimulated to increase the rate of their cell cycles. B) Only B cells are produced from stem cells of the bone marrow. C) T cells but not B cells can directly attack and destroy invading pathogens. D) T cells but not B cells have surface markers. E) Only B cells take part in cell-mediated immunity. |
C)
T cells but not B cells can directly attack and destroy invading pathogens |
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The MHC is important in a T cell's ability to
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distinguish self from nonself
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A patient can produce antibodies against some bacterial pathogens, but he does not produce antibodies against viral infections. This is probably due to a disorder in which cells of the immune system?
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T cells
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In which of the following situations will helper T cells be activated?
A) when an antigen is displayed by a dendritic cell B) when a cytotoxic T cell releases cytokines C) when natural killer (NK) cells come in contact with a tumor cell D) in the bone marrow during the self-tolerance test E) when B cells respond to T-independent antigens |
A)
when an antigen is displayed by a dendritic cell |
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An immunoglobulin (Ig) molecule, of whatever class, has regions symbolized as C or V, H or L. A light chain has which of these regions?
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one C and one V region
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For one person to produce over a million different antibody molecules could not possibly require over a million different genes. Instead, this variability is accounted for by which processes?
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DNA rearrangements followed by alternative splicing of the transcripts
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Which of the following is accounted for by immunological memory?
A) the human body's ability to distinguish self from nonself B) the observation that some strains of the pathogen that causes dengue fever cause worse disease than others C) the ability of a helper T cell to signal B cells via cytokines D) the ancient observation that someone who had recovered from the plague could safely care for those newly diseased E) the ability of the immune system to present antigen fragments in association with MHC antigens |
D)
the ancient observation that someone who had recovered from the plague could safely care for those newly diseased |
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These cells are involved in cell-mediated immunity and destroy virally infected cells
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cytotoxic T cells
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These cells are involved in cell-mediated immunity, and they respond to class I MHC molecule-antigen complexes
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cytotoxic T cells
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These cells are involved in innate immunity, and a person lacking these cells may have a higher than normal chance of developing malignant tumors
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natural killer cells
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Which of the following is a pathway that would lead to the activation of cytotoxic T cells?
A) B cell contact antigen → helper T cell is activated → clonal selection occurs B) body cell becomes infected with a virus → new viral proteins appear → class I MHC molecule-antigen complex displayed on cell surface C) self-tolerance of immune cells → B cells contact antigen → cytokines released D) complement is secreted → B cell contacts antigen → helper T cell activated → cytokines released E) cytotoxic T cells → class II MHC molecule-antigen complex displayed → cytokines released → cell lysis |
B)
body cell becomes infected with a virus → new viral proteins appear → class I MHC molecule-antigen complex displayed on cell surface |
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Which of the following is the last line of defense against an extracellular pathogen?
A) lysozyme production B) phagocytosis by neutrophils C) antibody production by plasma cells D) histamine release by basophils E) lysis by natural killer cells |
C)
antibody production by plasma cells |
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The following events occur when a mammalian immune system first encounters a pathogen. Which shows the correct sequence in which they occur?
I. Pathogen is destroyed. II. Lymphocytes secrete antibodies. III. Antigenic determinants from pathogen bind to antigen receptors on lymphocytes. IV. Lymphocytes specific to antigenic determinants from pathogen become numerous. V. Only memory cells remain. |
E)
III → IV → II → I → V |
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Which cell type interacts with both the humoral and cell-mediated immune pathways?
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helper T cells
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Both lysozyme and cytotoxic T cells
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kill cells through chemical interactions
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A nonfunctional CD4 protein on a helper T cell would result in the helper T cell being unable to
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interact with a class II MHC-antigen complex
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What are CD4 and CD8?
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molecules present on the surface of T cells where they enhance cellular interaction
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Which of the following are T cells of the immune system?
A) CD4, CD8, and plasma cells B) cytotoxic and helper cells C) plasma, antigen-presenting, and memory cells D) lymphocytes, macrophages, and dendritic cells E) class I MHC, class II MHC, and memory cells |
B)
cytotoxic and helper cells |
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B cells interacting with helper T cells are stimulated to differentiate when
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helper T cells release cytokines
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Why can normal immune responses be described as polyclonal?
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Diverse antibodies are produced for different epitopes of a specific antigen.
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How do antibodies of the different classes IgM, IgG, IgA, IgD, and IgE differ from each other ?
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in their heavy chain structure
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When antibodies attack antigens, clumping of the affected cells generally occurs. This is best explained by
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the shape of the antibody with at least two binding regions
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Phagocytosis of microbes by macrophages is enhanced by which of the following?
A) the binding of antibodies to the surface of microbes. B) antibody-mediated agglutination of microbes. C) the release of cytokines by activated B cells. D) A and B only E) A, B, and C |
D)
A and B only |
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What is the primary function of humoral immunity?
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It produces antibodies that circulate in body fluids
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Naturally acquired passive immunity would involve the
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placental transfer of antibodies
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Which of the following is true of active but not passive immunity?
A) acquisition and activation of antibodies. B) proliferation of lymphocytes in bone marrow. C) transfers antibodies from the mother across the placenta. D) requires direct exposure to a living or simulated pathogen. E) requires secretion of interleukins from macrophages. |
D)
requires direct exposure to a living or simulated pathogen |
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Jenner successfully used cowpox virus as a vaccine against the virus that causes smallpox
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There are some antigenic determinants common to both pox viruses.
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Which of the following would be most beneficial in treating an individual who has been bitten by a poisonous snake that has a fast-acting toxin?
A) vaccination with a weakened form of the toxin B) injection of antibodies to the toxin C) injection of interleukin-1 D) injection of interleukin-2 E) injection of interferon |
B)
injection of antibodies to the toxin |
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Which of the following is true of the successful development of a vaccine to be used against a pathogen?
A) It is dependent on the surface antigens of the pathogen not changing. B) It requires a rearrangement of the B cell receptor antibodies. C) It is not possible without knowing the structure of the surface antigens on the pathogen. D) It is dependent on the pathogen having only one epitope. E) It is dependent on MHC molecules being heterozygous |
A)
It is dependent on the surface antigens of the pathogen not changing |
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A researcher is analyzing the immune response of a patient following the patient's exposure to an unknown agent while out of the country. The patient's blood is found to have a high proportion of lymphocytes with CD8 surface proteins. What is the likely cause?
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The CD8 proteins marked the surfaces of cytotoxic T cells to attack virus-infected host cells.
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What accounts for antibody switching (i.e., the switch of one B cell from producing one class of antibody to another antibody class that is responsive to the same antigen)?
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the shuffling of exons for one C region type to another attached to the V-J transcript
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The number of MHC protein combinations possible in a given population is enormous. However, an individual in that population has only a couple of MHC possibilities. Why?
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Each of the MHC genes has a large number of alleles, but each individual only inherits 2 for each gene.
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A bone marrow transplant may not be appropriate from a given donor (Jane) to a given recipient (Jane's cousin Bob), even though Jane has previously given blood for one of Bob's needed transfusions. Which of the following might account for this?
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Jane's blood type is a match to Bob's but her MHC proteins are not
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A transfusion of type A blood given to a person who has type O blood would result in
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the recipient's anti-A antibodies clumping the donated red blood cells
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An immune response to a tissue graft will differ from an immune response to a bacterium because
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MHC molecules of the donor may stimulate rejection of the graft tissue
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A child is diagnosed with DiGeorge syndrome (DGS). With which of the following would the child have serious immunological problems?
A) production of antibodies B) rate of mitosis in plasma cells C) response to infection by a bacterium such as streptococcus D) response to infection by a virus such as influenza E) response to allergens such as bee venom |
D)
response to infection by a virus such as influenza |
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Which of the following might be a child with Bruton's disease?
A) baby girl Denise, with low level of antibody response to streptococcal infection B) baby boy John, with immature T cells, missing CD4 receptors C) baby boy Jeff, with no plasma cells following infection by bacterial pneumonia D) baby girl Susan, with no evidence of a thymus gland E) baby boy Matt, with very low circulating antigens |
C)
baby boy Jeff, with no plasma cells following infection by bacterial pneumonia |
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Bruton's disorder might occur because of which of the following molecular problems?
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A)
failure of heavy chain rearrangement in B cells |
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The DGS-like phenotype can be produced in a specific knockout mouse for HA3, a Hox gene. HA3 is known to be involved in developmental regulation in the mouse. Which of the following would be an appropriate test for following the gene in the mouse progeny?
A) bone marrow biopsy B) assay for environmental agents known to cause birth defects C) chest X-ray D) measurement of the proportion of CD4 cells to total lymphocytes E) autopsy examination of the thymus |
D)
measurement of the proportion of CD4 cells to total lymphocytes |
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In the human disease known as lupus, there is an immune reaction against a patient's own DNA from broken or dying cells. This kind of response typifies which kind of irregularity?
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autoimmune disease
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A patient undergoes a high level of mast cell degranulation, dilation of blood vessels, and acute drop in blood pressure. These symptoms could be caused by which of the following?
A) an autoimmune disease B) a typical allergy that can be treated by antihistamines C) an organ transplant, such as a skin graft D) the effect of exhaustion on the immune system E) anaphylactic shock immediately following exposure to an allergen |
E)
anaphylactic shock immediately following exposure to an allergen |
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Some pathogens can undergo rapid changes resulting in antigenic variation. Which of the following is such a pathogen?
A) the influenza virus, which expresses alternative envelope proteins B) the strep bacteria, which can be communicated from patient to patient with high efficiency C) human papilloma virus, that can remain latent for several years D) the causative agent of an autoimmune disease such as rheumatoid arthritis E) multiple sclerosis, that attacks the myelinated cells of the nervous system |
A)
the influenza virus, which expresses alternative envelope proteins |
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Some viruses can undergo latency, the ability to remain inactive for some period of time. Which of the following is an example?
A) influenza, a particular strain of which returns every 10-20 years B) herpes simplex viruses (oral or genital) whose reproduction is triggered by physiological or emotional stress in the host C) Kaposi's sarcoma, which causes a skin cancer in people with AIDS, but rarely in those not infected by HIV D) the virus that causes a form of the common cold, which recurs in patients many times in their lives E) myasthenia gravis, an autoimmune disease that blocks muscle contraction from time to time |
B)
herpes simplex viruses (oral or genital) whose reproduction is triggered by physiological or emotional stress in the host |
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Most newly emerging diseases, no matter how severe their effects on a population, human or otherwise, have which of the following in common?
A) greater severity as there are more and more occurrences of the infection B) major pandemics, spreading the infection far and wide in the population C) a tendency to die out rather quickly, cease to reproduce, or cause a less severe effect on the host D) a destruction of the host immune system and eventual cancer E) no discoverable relationship with other pathogens in the same or related species |
C)
a tendency to die out rather quickly, cease to reproduce, or cause a less severe effect on the host |
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Which of the following could prevent the appearance of the symptoms of an allergy attack?
A) blocking the attachment of the IgE antibodies to the mast cells B) blocking the antigenic determinants of the IgM antibodies C) reducing the number of helper T cells in the body D) reducing the number of cytotoxic cells E) reducing the number of natural killer cells |
A)
blocking the attachment of the IgE antibodies to the mast cells |
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patient reports severe symptoms of watery, itchy eyes and sneezing after being given a flower bouquet as a birthday gift. A reasonable initial treatment would involve the use of
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antihistamines
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What aspect of the immune response would a patient who has a parasitic worm infection and another patient responding to an allergen such as ragweed pollen have in common?
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Both patients would have increased levels of IgE.
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Which of the following is not a component of an insect's defense against infection?
A) enzyme activation of microbe-killing chemicals B) activation of natural killer cells C) phagocytosis by hemocytes D) production of antimicrobial peptides E) a protective exoskeleton |
B)
activation of natural killer cells |
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Which of the following is a characteristic of the early stages of local inflammation?
A) anaphylactic shock B) fever C) attack by cytotoxic T cells D) release of histamine E) antibody- and complement-mediated lysis of microbes |
D)
release of histamine |
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An epitope associates with which part of an antibody?
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variable regions of a heavy chain and light chain combined
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Which of the following is not true about helper T cells?
A) They function in cell-mediated and humoral responses. B) They recognize polysaccharide fragments presented by class II MHC molecules. C) They bear surface CD4 molecules. D) They are subject to infection by HIV. E) When activated, they secrete cytokines. |
B)
They recognize polysaccharide fragments presented by class II MHC molecules. |
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Which statement best describes the difference in responses of effector B cells (plasma cells) and cytotoxic T cells?
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B cells secrete antibodies against a virus; cytotoxic T cells kill virus-infected cells
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Which of these molecules is incorrectly paired with a source?
A) Lysozyme tears B) Interferons virus-infected cells C) Antibodies B cells D) Chemokines cytotoxic T cells E) Cytokines helper T cells |
D)
Chemokines cytotoxic T cells |
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Which of the following results in long-term immunity?
A) the passage of maternal antibodies to a developing fetus B) the inflammatory response to a splinter C) the administration of serum obtained from people immune to rabies D) the administration of the chicken pox vaccine E) the passage of maternal antibodies to a nursing infant |
D)
the administration of the chicken pox vaccine |
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HIV targets include all of the following except
A) macrophages. B) cytotoxic T cells. C) helper T cells. D) cells bearing CD4. E) brain cells. |
B)
cytotoxic T cells |