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