LS7C LaunchPad Week 3

Practice Exam Questions Week 3

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Arrange the events in the stimulation of heart muscle in order from earliest (1) to latest (5). Note that this question does not list every step in the pathway, but the steps presented should be arranged in order. Activation of adenylyl cyclase Activation of G-proteins Activation of protein kinase A Phosphorylation of proteins that induce contraction in muscle cells Conversion of ATP into cyclic AMP

2 1 4 5 3

Pre-class review questions 38.1

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Pre-class review questions 42.2

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Animation: Peptide and steroid hormones

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Animation: Signal Amplification

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Animation: Blood Glucose

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Animation: G protein

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Pre-class review questions 38.2

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Pre-class review questions 38.4

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Animation: Hypothalamus

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Pre-class reading questions 42.3

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Pre-class review questions 38.3

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Animation: Cell Signaling

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Pre-class review questions 9.4

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When a person has a few drinks containing alcohol, they often feel the need to urinate. This response suggests interplay between alcohol and antidiuretic hormone (ADH). Which of the following could explain how alcohol and ADH interact? (note: ADH causes a decrease in urine production) Alcohol increases the release of ADH. Alcohol decreases the release of ADH. Alcohol facilitates the binding of ADH to receptors in the brain, so individuals "feel" the need to urinate. Alcohol inhibits the binding of ADH to receptors in the brain, so individuals "feel" the need to urinate.

Alcohol decreases the release of ADH.

Aldosterone, in the figure below, is a hormone secreted by the adrenal cortex, and insulin is a peptide secreted by the pancreas. When aldosterone contacts a target cell, it binds to an intracellular receptor and migrates to the nucleus; insulin binds to extracellular receptors on the plasma membrane. What is the MOST likely reason for this difference? Aldosterone is hydrophilic and, therefore, must enter the aqueous environment of the cytoplasm to have an effect. Insulin is too large to interact chemically with DNA. Aldosterone is too small to bind extracellular receptors on the plasma membrane. Aldosterone is lipid-soluble and, therefore, easily crosses the phospholipid bilayer of the plasma membrane.

Aldosterone is lipid-soluble and, therefore, easily crosses the phospholipid bilayer of the plasma membrane.

Positive feedback loops: move the system farther and farther away from the set point. continue until interrupted or broken by an external signal. All of these choices are correct. cause a response in the same direction as the initial stimulus. are activated by a stimulus.

All of these choices are correct.

Second messengers: are small intracellular molecules that participate in signal transduction. amplify the effects of the signal. All of these choices are correct. are removed in order to terminate a cellular signaling response. play a role in activation of intracellular signal transduction.

All of these choices are correct.

Termination is an important step in adrenaline signaling because it: allows organisms to respond to new stresses. prevents an excessive response to adrenaline. allows an appropriate level of response. All of these choices are correct.

All of these choices are correct.

The type of signaling cascade shown in the video directly affects which of these animal tissue types? A.nerve B.muscle C.connective D.epithelial

B.muscle

Many birth-control pills release a constant amount of synthetic estradiols and progesterone for 21 days, followed by 7 days when no hormones are ingested. Which of the following statements MOST accurately describes the effects of birth-control pills? Birth-control pills maintain constant levels of estrogens and/or progesterone so there is no surge in LH and ovulation does not occur. The 7 days with no hormones does not allow a thick enough uterine lining to form so a fertilized oocyte cannot implant. Birth-control pills maintain constant levels of estrogens and/or progesterones and mask the release of the oocyte from the follicle. Birth-control pills inhibit the development of the uterine lining so implantation of a fertilized oocyte cannot occur.

Birth-control pills maintain constant levels of estrogens and/or progesterone so there is no surge in LH and ovulation does not occur.

Adrenaline stimulates an increase in heart rate by binding to: A.nuclear transport proteins that allow adrenaline to be taken into the nucleus to act as a transcription factor. B.adenylyl cyclase. C.G-protein coupled receptors on the surface of cardiac muscle cells. D.G-proteins on the cytosolic face of the plasma membrane. E.regulatory regions in genes that code for muscle cell proteins.

C.G-protein coupled receptors on the surface of cardiac muscle cells.

Termination of the adrenaline signal begins when: A.ATP gets converted into cyclic AMP. B.GDP bound to the G-protein is exchanged for GTP. C.GTP bound to the G-protein alpha subunit is hydrolyzed to GDP and Pi. D.the molecules of adrenaline are transported into the cell and degraded. E.G-protein coupled receptors are removed from the cell membrane.

C.GTP bound to the G-protein alpha subunit is hydrolyzed to GDP and Pi.

Assume you haven't eaten in the last 24 hours. Which of the following would you predict? Choice A., Glucagon release from the pancreas will increase. Choice B., Insulin release from the pancreas will increase. Choice C., Glucagon release from the pancreas will decrease. Choice D., Glycogen storage by the liver will increase.

Choice A., Glucagon release from the pancreas will increase.

If a mutation caused the G protein to become permanently bound to GTP, what result can be predicted? Choice A., It constantly signals its pathway to be "on." Choice B., It constantly signals its pathway to be "off." Choice C., It is unable to signal subsequent steps in the pathway. Choice D., It is unable to separate from the beta and gamma subunits.

Choice A., It constantly signals its pathway to be "on."

In vertebrates, the nervous system directly interacts with the _________ to control endocrine function in the body. Choice A., hypothalamus Choice B., anterior pituitary Choice C., posterior pituitary Choice D., adrenal cortex

Choice A., hypothalamus

Muscle and liver cells respond to insulin by: Choice A., taking up glucose and storing it as glycogen. Choice B., breaking down glycogen and releasing glucose. Choice C., breaking down glycogen and storing glucose. Choice D., breaking down glucose and releasing glycogen

Choice A., taking up glucose and storing it as glycogen.

In the example of adrenaline signaling used in the animation, suppose each amplification step produces hundredfold active molecules. A signaling pathway resulting from a single activated signal receptor results in the consumption of _______ molecules of GTP and _______ molecules of ATP. Choice A., 100; 1,000,000 Choice B., 100; 1,010,000 Choice C., 1; l00 Choice D., 10,000; 1,000,000

Choice B., 100; 1,010,000

Which of the following statements best summarizes the function of G protein-coupled receptors? Choice A., A G protein present on the outside of the cell leads to a change on the inside of the cell. Choice B., A signal present on the outside of the cell leads to a change on the inside of the cell. Choice C., A signal molecule on the outside of the cell is transported to the inside of the cell. Choice D., A GTP molecule is bound to the receptor, which causes a conformational change inside the cell.

Choice B., A signal present on the outside of the cell leads to a change on the inside of the cell.

Which of the following best describes the function of the hypothalamus? Choice A., The hypothalamus produces the hormones that make up the endocrine system. Choice B., The hypothalamus connects the nervous system to the endocrine system. Choice C., The pituitary gland is that part of the hypothalamus that produces hormones. Choice D., The hypothalamus has endocrine hormone receptors that trigger the action potentials of the neurosecretory cells.

Choice B., The hypothalamus connects the nervous system to the endocrine system.

In the example of adrenaline signaling, which steps represent an amplification of the signal? Choice A., activated receptor activates G proteins, G protein binding by GTP, cyclic AMP activation of protein kinase A Choice B., activated receptor activates G proteins, activated adenylyl cyclase produces cAMP, active protein kinase A phosphorylates target proteins Choice C., receptor signal binding, activated receptor activates G proteins, activated adenylyl cyclase producing cAMP Choice D., receptor signal binding, activated adenylyl cyclase producing cAMP, active protein kinase A phosphorylating target proteins

Choice B., activated receptor activates G proteins, activated adenylyl cyclase produces cAMP, active protein kinase A phosphorylates target proteins

Insulin injections are an important treatment for some diabetics. A serious potential side effect of insulin injections is hypoglycemia (low blood sugar). This would most likely occur under which of the following circumstances? Choice A., failure to inject enough insulin Choice B., injecting too much insulin Choice C., failure to inject any insulin

Choice B., injecting too much insulin

You are working with a team of scientists who are investigating the biochemical control system involved in how animals digest fats in their meals. You have evidence that there must be a signal molecule involved that is released soon after the fats are consumed. When this signal molecule is present it triggers activation of appropriate digestive enzymes and cellular uptake transporters until the meal has been fully digested. Based on this information, what type of signal molecule would you predict is involved in this process? Choice A., hydrophobic hormone Choice B., peptide or amine hormone Choice C., cAMP Choice D., steroid hormone Choice E., protein kinase

Choice B., peptide or amine hormone

The hypothalamus uses action potentials to directly stimulate hormone release from: Choice A., the anterior pituitary only. Choice B., the posterior pituitary only. Choice C., both the anterior and posterior pituitary. Choice D., neither the anterior nor the posterior pituitary.

Choice B., the posterior pituitary only.

Which of the following is false? Choice A., The actions of both the beta and alpha cells in the pancreas are stimulated or inhibited by the amount of glucose they detect in the blood as it passes through the pancreas. Choice B., In the pancreas, the action of the beta cells opposes the action of the alpha cells in regulating blood glucose levels. Choice C., High blood glucose levels can result from an overproduction of insulin. Choice D., The pancreas releases glucagon into the blood in response to low blood sugar and releases insulin into the blood in response to high blood sugar.

Choice C., High blood glucose levels can result from an overproduction of insulin.

When an appropriate signal binds to a G protein-coupled receptor, what is the best description of how the information is passed across the Choice A., Binding of the signal molecule triggers the cell to produce G protein. Choice B., The signal molecule is transported across the plasma membrane by the receptor protein. Choice C., Signal binding causes a conformational change in the cytoplasmic portion of receptor protein.

Choice C., Signal binding causes a conformational change in the cytoplasmic portion of receptor protein.

Which of the following steps does not result in an amplification of the signal information? Choice A., activation of G protein by activated receptor Choice B., production of cyclic AMP by adenylyl cyclase Choice C., activation of adenylyl cyclase by active G protein Choice D., phosphorylation of target proteins by protein kinase A

Choice C., activation of adenylyl cyclase by active G protein

G protein-coupled receptors are found: Choice A., in the cytoplasm. Choice B., on the nuclear membrane. Choice C., on the cell surface. Choice D., inside the nucleus.

Choice C., on the cell surface.

The pituitary gland and a part of the hypothalamus are among only a few parts of the brain that are not protected by the blood-brain barrier. One explanation for this could be: Choice A., they are not actually part of the brain. Choice B., they cannot produce sufficient hormone quantity without a blood supply. Choice C., the barrier would block hormone secretion. Choice D., the toxic substances blocked by the barrier do not affect them. Choice E., they developed from epithelial cells, not neurons.

Choice C., the barrier would block hormone secretion.

In the example of adrenaline signaling used in the animation, suppose each amplification step produces hundredfold active molecules. How many total modified protein target molecules result from a single activated signal receptor? Choice A., 300 Choice B., 900 Choice C., 10,000 Choice D., 1,000,000 Choice E., 100,000,000

Choice D., 1,000,000

When a G protein-coupled receptor binds a signal molecule, it activates a G protein. The active G protein is bound to a molecule of _______BLANK, and in its active state can _________BLANK. Choice A., GDP; inactivate another target protein Choice B., GTP; inactivate another target protein Choice C., GDP; activate another target protein Choice D., GTP; activate another target protein

Choice D., GTP; activate another target protein

High blood glucose stimulates the _________ cells in the pancreas to secrete _________. Choice A., alpha; glucagon Choice B., beta; glucagon Choice C., alpha; insulin Choice D., beta; insulin

Choice D., beta; insulin

The primary advantage of a signaling cascade is that it: A.limits an abundant extracellular signal to a smaller intracellular response. B.allows extracellular molecules to be taken into the cell to initiate a response. C.allows a cell to quickly shut off all phosphorylation events inside that cell without the signaling molecule itself entering the cell. D.allows a large intracellular response from a small number of extracellular signal molecules. E.provides a mechanism to use a single signaling molecule to produce a response in multiple cells

D.allows a large intracellular response from a small number of extracellular signal molecules.

The alpha subunit of a G-protein is free to diffuse in the plane of the membrane when: A.GTP is hydrolyzed into GDP and Pi. B.the alpha subunit gets phosphorylated. C.cyclic AMP binds to it. D.the alpha subunit gets dephosphorylated. E.GDP is exchanged for GTP.

E.GDP is exchanged for GTP.

Which of the following statements correctly describe(s) peptide hormones? Select all that apply. Insulin and glucagon are good examples of peptide hormones. Most peptide hormones act on cells by binding to receptors on cell surfaces and triggering signaling cascades inside the cell. Enzymes modify cholesterol compounds to produce peptide hormones. The action of peptide hormones can cause changes in gene expression or can affect the function of metabolic enzymes in cells. Peptide hormones bind to intracellular receptors and the peptide-receptor complex acts as a transcription factor.

Insulin and glucagon are good examples of peptide hormones. Most peptide hormones act on cells by binding to receptors on cell surfaces and triggering signaling cascades inside the cell. The action of peptide hormones can cause changes in gene expression or can affect the function of metabolic enzymes in cells.

A key difference between hormonal regulation of the reproductive systems of males and females is that: LH and FSH are released only in females. LH and FSH are released only in males. LH and FSH are released cyclically in females but nearly continuously in males. LH is released continuously in males and FSH is released cyclically in females. LH is released in males and FSH is released in females.

LH and FSH are released cyclically in females but nearly continuously in males.

What is the difference between negative feedback and positive feedback mechanisms? Negative feedback mechanisms move a system away from a set point; positive feedback mechanisms stabilize a system at a set point. Negative feedback mechanisms return a system to a set point; positive feedback mechanisms amplify a response. Negative feedback mechanisms stabilize a system at a set point; positive feedback mechanisms change the set point.

Negative feedback mechanisms return a system to a set point; positive feedback mechanisms amplify a response.

_____ are chemical signals that, instead of being secreted into the bloodstream, are introduced by animals into their habitats. They can be used to attract mates and mark territories. Growth factors Pheromones Neurotransmitters Hormones

Pheromones

How do mitogen-activated protein (MAP) kinases become inactive? Ras hydrolyzes GTP to GDP. Ligand diffuses away from the ligand-binding site. Receptor kinases move apart in the membrane. Phosphatases remove phosphate groups.

Phosphatases remove phosphate groups.

Which of the following does NOT occur during the follicular phase of the menstrual cycle? The uterine lining is shed. Ten to twelve oocytes begin to mature. FSH levels increase. All of these choices are correct. Progesterone levels increase to high levels.

Progesterone levels increase to high levels.

Why are some body cells responsive to a particular hormone, whereas others are not? All of these choices are correct. Responsive cells have complex signal transduction pathways, whereas cells that do not respond to a particular hormone lack these pathways. Whether or not a cell responds to a hormone depends entirely on what type of cell it is (liver cell vs. fat cell vs. nerve cell), because hormones only activate one type of cell. Responsive cells express a receptor specific for the hormone. Responsive cells are located closer to the gland that releases the hormone.

Responsive cells express a receptor specific for the hormone.

Which of the following correctly describe(s) the functioning of steroid hormones in the animal endocrine system? Select all that apply. Steroid hormones can change which mRNAs are produced in a cell. Steroid hormones have their primary effects in the cell's nucleus In general, peptide hormones are slower to act than steroid hormones and their actions last longer than those of steroid hormones. Steroid hormones bind to cell-surface receptors, which then trigger second messengers.

Steroid hormones can change which mRNAs are produced in a cell. Steroid hormones have their primary effects in the cell's nucleus

How is synaptic signaling different from paracrine signaling? Synaptic signaling specifically involves neurotransmitters that are released from neurons. All of these choices are correct. Synaptic signaling acts over a longer distance than paracrine signaling. Synaptic signaling is longer in duration than paracrine signaling. Synaptic signaling requires receptors to elicit a response in the target cell.

Synaptic signaling specifically involves neurotransmitters that are released from neurons.

When iodine intake is too low, production of _____ by the anterior pituitary gland _____. TSH; increases TSH; decreases thyroxine; increases thyroxine; decreases triiodothyronine; decreases

TSH; increases

Which of the following are true for the hypothalamus and pituitary gland? Select all that apply. The general chemical nature of a hormone can be used to predict: The action of the neurons from the hypothalamus is direct for the posterior pituitary, that is, the neurons extend from the hypothalamus to the posterior pituitary where the axon terminal releases hormones that go directly into the blood. The action of the neurons from the hypothalamus is indirect for the anterior pituitary, that is, the action potentials in the neurons in the hypothalamus cause formation of new action potentials in different neurons in the anterior pituitary. Neurosecretory cells of the hypothalamus secrete releasing factors that enter the anterior pituitary via a portal system to cause release of hormones from the anterior pituitary. Release factors from neurosecretory cells of the hypothalamus cause release of hormones into the blood from the posterior pituitary gland. Release factors from the posterior pituitary stimulate release of specific hormones into the blood from the anterior pituitary.

The action of the neurons from the hypothalamus is direct for the posterior pituitary, that is, the neurons extend from the hypothalamus to the posterior pituitary where the axon terminal releases hormones that go directly into the blood. Neurosecretory cells of the hypothalamus secrete releasing factors that enter the anterior pituitary via a portal system to cause release of hormones from the anterior pituitary.

If secretion of adrenocorticotropic hormone (ACTH) is inhibited, then which of the following will result? The adrenal glands would not release cortisol. None of the answer options is correct. The thyroid gland would not release thyroid hormone. The anterior pituitary gland would not release TSH. The posterior pituitary gland would not release ADH.

The adrenal glands would not release cortisol.

What causes the inactivation of a G protein? The beta and gamma subunits trigger the hydrolysis of GTP to GDP. The alpha subunit catalyzes the hydrolysis of GTP to GDP and inorganic phosphate. A phosphatase removes the inorganic phosphate group from GTP. The inactive receptor catalyzes the replacement of GTP by GDP.

The alpha subunit catalyzes the hydrolysis of GTP to GDP and inorganic phosphate.

Which of the following are correct descriptions about the pituitary gland? Select all that apply. The general chemical nature of a hormone can be used to predict: The pituitary gland controls signaling from the hypothalamus. The anterior pituitary gland is under the control of the hypothalamus. The posterior pituitary gland is under the control of the hypothalamus. The pituitary gland acts as the control center for most other endocrine glands in the body. Even though the anterior and posterior pituitary have distinctly different functions, they formed from the same embryonic tissue.

The anterior pituitary gland is under the control of the hypothalamus. The posterior pituitary gland is under the control of the hypothalamus. The pituitary gland acts as the control center for most other endocrine glands in the body.

Which of the following statements about the corpus luteum is FALSE? None of the other answer options is false. Progesterone secreted by the corpus luteum maintains the uterine lining. The corpus luteum is maintained first by FSH and then by hCG. If the egg is not fertilized then the corpus luteum degenerates. It is composed of follicle cells that remain in the ovary following ovulation.

The corpus luteum is maintained first by FSH and then by hCG.

A botanist working in the Amazon rain forest discovers a new species of orchid. Interestingly, males but not females of a certain wasp species keep visiting the flowers of these orchids. Why? Male wasps are likely attracted by growth factors produced by the orchid. Male wasps are likely attracted by paracrine signals produced by the orchid. The orchid might produce a pheromone similar to that produced by female wasps. Male wasps are likely attracted to the bright colors of the orchids' flowers. Male wasps are likely attracted to the sweet nectar produced by the orchid.

The orchid might produce a pheromone similar to that produced by female wasps.

Oxytocin and cholecystokinin are transported through the bloodstream and arrive at the uterus at the same time. Oxytocin causes the uterus to contract, whereas cholecystokinin has no effect. Why? The uterus has receptors for oxytocin, but not for cholecystokinin. Oxytocin can diffuse through the plasma membrane of uterine cells, whereas cholecystokinin cannot. Oxytocin is at a higher concentration in the bloodstream than cholecystokinin. Oxytocin blocks the activity of cholecystokinin. Oxytocin alters gene expression patterns, whereas cholecystokinin does not.

The uterus has receptors for oxytocin, but not for cholecystokinin.

Which of the following statements about K-strategists is FALSE? They evolve in stable environments. There is a lot of parental investment in the offspring. They evolve in environments with intense competition for limited food. They produce few offspring. They give birth frequently.

They give birth frequently.

Which of the following could lead to a prolonged increase in heart rate, even in the absence of an external signal? Choose all that apply. a. An inability of a G-protein to hydrolyze GTP b. An inability to inactivate protein kinase A c. An inability of G-protein coupled receptors to bind adrenaline d. An inability of cyclic AMP to activate protein kinase A e. An inability to convert ATP into cyclic AMP

a b

A new hormone has been isolated from an organism. Although the structure of the hormone has not yet been determined, the hormone is known to exert its effects by forming a hormone-receptor complex that acts as a transcription factor within target cells. What type of hormone is this MOST likely to be? either a steroid hormone or an amine hormone either an amine or a peptide hormone either a steroid or a peptide hormone a peptide hormone a steroid hormone

a steroid hormone

Tropic hormones: act on other endocrine organs. suppress the immune system. regulate the metabolic state of the body. are released from the thyroid gland. suppress the appetite.

act on other endocrine organs.

The two main classes of hormones are: amine/peptide hormones and steroid hormones. lipid-soluble hormones and water-soluble hormones. polysaccharide hormones and protein hormones. steroid hormones and lipid hormones. nucleic acid hormones and lipid hormones.

amine/peptide hormones and steroid hormones.

Animals faced challenges when moving from water to land. What was the single most important adaptation that led to the uncoupling of reproduction and the need for an aquatic habitat? amniotic egg internal fertilization flagellated sperm

amniotic egg

Inactivation of a cell-surface receptor depends on: the binding affinity of the receptor. the activity of phosphatases in the cytosol. the concentration of ligand surrounding the cell. both the binding affinity of the receptor and concentration of ligand surrounding the cell.

both the binding affinity of the receptor and concentration of ligand surrounding the cell.

When circulating _____ levels are too high, production of parathyroid hormone would be _____. calcium; inhibited cortisol; inhibited glucose; stimulated calcium; stimulated glucose; inhibited

calcium; stimulated

A newly developed drug works by blocking thyroid hormone receptors throughout the body. Which of the following would be expected to occur in a patient who is taking this drug? increased uptake of glucose by body cells inability to release cortisol decreased resorption of bone production of more dilute urine changes in metabolism

changes in metabolism

When a doctor suspects that a patient may have diabetes, she will often have the patient take a glucose challenge test. After the patient drinks a large amount of sugary solution, his blood is drawn and the circulating levels of glucose in the blood are determined. Which of the following curves do you expect from a patient with diabetes? curve C curve A curve B

curve B

Kisspeptin is a protein in humans that has an important role in initiating secretion of the releasing factor gonadotropin-releasing hormone (GnRH). Endocrinologists are finding that the protein kisspeptin and its receptor are central to sexual maturation at puberty. Neurons that release kisspeptin carry estrogen receptors. If this is a negative feedback system, high levels of estrogen would be expected to: neither increase nor decrease kisspeptin synthesis because steroid hormones do not affect protein synthesis. decrease kisspeptin synthesis. increase kisspeptin synthesis.

decrease kisspeptin synthesis.

Which of the following insect hormones acts on the body tissues to stimulate molting and metamorphosis? All of these choices are correct. juvenile hormone ecdysone brain peptide PTTH

ecdysone

A researcher is working with mutant mice that demonstrate defects in the formation of connective tissue. These mice likely carry a mutation in a gene encoding what type of growth factor? histamine neurotransmitters nerve growth factors (NGFs) fibrinogen growth factors (FGFs) bone morphogenetic proteins (BMPs)

fibrinogen growth factors (FGFs)

An individual who is experiencing a prolonged period of stress would likely have _____ levels of circulating _____ than an individual who was not experiencing stress. higher; ADH lower; ADH lower; cortisol higher; cortisol lower; ACTH

higher; cortisol

Which of the following statements correctly describe(s) the relationship between the classes of hormones and their behavior or function? Select all that apply. The general chemical nature of a hormone can be used to predict: how soluble the hormone is in water. whether the hormone will be able to move through the cell membrane. whether the hormone interacts with receptors on the cell membrane. whether the hormone interacts with receptors inside the cell. whether the hormone will increase or decrease a specific cell function.

how soluble the hormone is in water. whether the hormone will be able to move through the cell membrane. whether the hormone interacts with receptors on the cell membrane. whether the hormone interacts with receptors inside the cell.

Ovulation is triggered by a surge of which of the following hormones? luteinizing hormone estrogen testosterone follicle stimulating hormone progesterone

luteinizing hormone

At which point on the phylogeny shown did the amnion FIRST appear? node B node E node A node C node D

node C

Oocytes are produced in which of the following structures? fallopian tubes vagina cervix uterus ovaries

ovaries

Which of the following is the CORRECT path taken by sperm from site of production to site of ejection? epididymis, seminiferous tubules, vas deferens, urethra, ejaculatory duct seminiferous tubules, epididymis, vas deferens, ejaculatory duct, urethra vas deferens, epididymis, seminiferous tubules, ejaculatory duct, urethra epididymis, seminiferous tubules, vas deferens, ejaculatory duct, urethra seminiferous tubules, vas deferens, ejaculatory duct, epididymis, urethra

seminiferous tubules, epididymis, vas deferens, ejaculatory duct, urethra

The hormone indicated by the small hexagon on the lower left in the figure could be which of the following? growth hormone insulin testosterone ADH

testosterone

The hormone indicated by the small hexagon on the lower left in the figure could be which of the following? growth hormone testosterone ADH insulin

testosterone

In response to LH and FSH, testes secrete: sperm. ejaculate. testosterone. TDF. estrogen.

testosterone.

Which of the following is an example of a negative feedback altering homeostatic control? a person's heart rate drops as she runs a person shivering as temperatures rise on a hot summer day the concentration of salt in urine increases after eating a large bag of salty chips the production of oxytocin (a hormone) increases as oxytocin levels rise in the body

the concentration of salt in urine increases after eating a large bag of salty chips

In vertebrates, which of the following frequently serves as the first intermediary between the areas of the brain that perceive sensory stimuli and the rest of the endocrine system? the adrenal glands the hypothalamus the thyroid gland the posterior pituitary gland the anterior pituitary gland

the hypothalamus

In the G protein-coupled signal transduction pathway, phosphatases are responsible for the inactivation of: All of these choices are correct. protein kinase A. adenylyl cyclase. the protein target activated by protein kinase A. the alpha subunit of a G protein.

the protein target activated by protein kinase A.

Some researchers have suggested that obesity is due to a change in "set point" in the brain that is related to the number of calories a person needs, therefore people eat more than they need and gain weight. Permanently raising the set point would involve a permanent change in which of the following? the sensor the effector the response the stimulus

the sensor

What is the function of adenylyl cyclase? to form cyclic AMP to form protein kinase A to phosphorylate protein kinase A to phosphorylate cyclic AMP

to form cyclic AMP

Pheromones are generally detected by the vomeronasal organ in most mammals, reptiles, and amphibians. T/F

true