Ion Inside Outside K Na

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1 Final Exam, 2008, Part 1 1. Which of the following statements about diffusion is FALSE? a. Molecules diffuse from regions of high concentration to regions of low concentration. b. The flux, J, is directly proportional to the concentration gradient. c. Diffusion tends to collapse concentration gradients. d. Diffusion is the result of the random motion of molecules. e. The distance molecules diffuse is directly proportional to time (L t). 2. The intracellular and extracellular concentrations (in mm) of K + and Na + are given below. If the membrane is equally permeable to the two ions, what will the membrane potential be? Ion Inside Outside K Na a. -86 mv b. -10 mv c. -4 mv (midway between V K and V Na ) d mv e mv 3. Which of the following is not a property of ion channels? a. Ion channels increase the permeability of the membrane to ions. b. Ion channels are integral membrane proteins. c. An ion channel is a pore that is not open at all times. d. Ion channels exhibit selectivity by allowing only certain ions to flow through the channel. e. Ion channels can cause ions to accumulate in cells to a concentration greater than the equilibrium concentration. 4. Which of the following events does not occur during the propagation of an action potential along a myelinated nerve axon? a. Propagation by local circuit current flow. b. Inward sodium current at one node of Ranvier causes outward current to flow at an adjacent node, which depolarizes the adjacent node to threshold. c. Na + channels become inactivated. d. Delayed rectifier K + channels open e. The action potential propagates rapidly from one node to the next.

Final Exam, 2008, Part 1 The following three questions relate to the picture of a portion of a plant shown to the right. 8. What are the structures indicated by arrows? a. Stomata b. Xylem tubes c.

Delayed rectifier K + channels e. Plasma membrane Ca 2+ ATPase 10. What is the major role of these structures? a. Photosynthesis b. Nitrogen fixation c. Water uptake from the soil d.

2 Final Exam, 2008, Part 1 The following three questions relate to the picture of a portion of a plant shown to the right. 8. What are the structures indicated by arrows? a. Stomata b. Xylem tubes c. Plasmadesmata d. Root hairs e. Companion cells 9. What protein is responsible for generating the membrane potential of these cells? a. Na-K ATPase b. H + ATPase c. L-type Ca 2+ channels d. Delayed rectifier K + channels e. Plasma membrane Ca 2+ ATPase 10. What is the major role of these structures? a. Photosynthesis b. Nitrogen fixation c. Water uptake from the soil d. CO 2 uptake from the air e. Sucrose synthesis The following two questions relate to the plant A B structure shown to the right. 11. What are the cells of the structure and where are they found? a. Mesophyll cells, in leaves b. Guard cells, in root hairs c. Guard cells, on the under side of leaves d. Guard cells, on the upper side of leaves e. Synergid cells, in the ovary 12. To cause the transition from A to B, what must occur? a. V m must become more negative b. The total solute concentration must become greater c. The cytoplasmic water potential, Ψ, must increase d. The H + ATPase must be activated e. Cl - enters via secondary active transport

3 Final Exam, 2008, Part Suppose that the cytoplasm of a marine algal cell contains 1.2 M total solutes and the surrounding sea water contains 1.0 M total solutes. If water is in equilibrium, what will be turgor pressure of the cell, assuming water is at equilibrium? a. 1 atm b. 2 atm c. 3 atm d. 4 atm e. 5 atm 19. The mechanism by which gibberellin causes amylase to be secreted by the aleurone cells of the barley seed is a. by enzymatically digesting starch b. by opening chloride channels, thus depolarizing the membrane potential c. by activating a proton ATPase, thus hyperpolarizing the membrane potential d. by binding to a plasma membrane receptor and thus causing an increase in cytosolic Ca 2+ e. by inducing the polar transport of auxin 20. The posterior determinant localized to the posterior pole of the Drosophila egg is a. bicoid mrna b. bicoid protein c. nanos mrna d. hunchback mrna e. hunchback protein 21. What does bicoid protein do? a. It activates Ca 2+ channels in the plasma membrane of the egg b. It is a transcription factor that regulates the production of huchback mrna c. It is a transcription factor that regulates the production of nanos mrna d. Nothing, because the mrna is never translated. e. It directs the formation of the pole cells. 22. Suppose that a cell gains 10 pmole of Na + during an action potential. How many ATP molecules will be used to return [Na + ] to the original (pre-action potential) level? a. 6 x b. 2 x c. 6 x d. 2 x (remember, each cycle of the pump expels 3 Na + per ATP used) e The active form of phytochrome a. is produced when the molecule absorbs a photon of 730 nm light b. requires the binding of 4 Ca 2+ to each molecule c. requires the absorption a photon of blue light d. is produced when the molecule absorbs a photon of 670 nm light e. regulates stomatal opening

4 Final Exam, 2008, Part The pigment of the amphibian egg marks the animal pole, but albino eggs lacking pigment develop normally. Thus, the functional polarity of the egg depends on some localized molecule other than pigment. Based on what you know about the Drosophila egg, what might that localized molecule be? a. ribosomes b. DNA c. acetylcholine d. norepinephrine e. mrna (but this question is ignored in the grading) 24. The role of the enzyme, carbonic anhydrase, is to a. modulate the affinity of hemoglobin for O 2 b. modulate the affinity of hemoglobin for CO 2 c. increase the permeability of capillary membranes for O 2 d. increase the permeability of capillary membranes for CO 2 e. speed the conversion of CO 2 to H 2 CO 3 and vice versa. 25. How is information about the strength of a stimulus encoded in the axons of an excitable cell? a. In the size of the action potentials b. In the frequency of the action potentials. c. In the duration of the action potentials d. In the rate of propagation of the action potentials. e. In the nature of the neurotransmitter released 26. What one condition must be satisfied in order for water to move into a root hair cell from the soil? a. the osmolarity must be greater in the cell than in the soil b. the osmolarity must be greater in the soil than in the cell c. the hydrostatic pressure must be greater in the cell than in the soil d. the water potential must be greater in the cell than in the soil e. the water potential must be greater in soil than in the cell 27. When a coleoptile responds to unilateral blue light a. auxin is transported away from the light and the coleoptile bends toward the light b. auxin is transported toward the light and the coleoptile bends toward the light c. auxin is transported toward the light and the coleoptile bends away from the light d. auxin is transported away from the light and the coleoptile bends away from the light e. the turning is mediated by phytochrome and auxin

5 Final Exam, 2008, Part The pressure in the pleural space of the vertebrate chest a. is always less than barometric pressure b. is always more than barometric pressure c. is always less that the pressure in the alveoli of the lung d. is always more than the pressure in the alveoli of the lung e. determines the rate of breathing 34. Using the diagram above, estimate the peak number of open sodium channels and peak number of open potassium channels in a 10 μm 2 patch of membrane during the action potential. a. 800 Na + channels, 400 K + channels b. 400 Na + channels, 400 K + channels c. 400 Na + channels, 250 K + channels d. 250 Na + channels, 400 K + channels e. 250 Na + channels, 800 K + channels 35. An action potential will be generated in a motor neuron if a. an excitatory input arrives at a dendrite b. an inhibitory input arrives at a dendrite c. the spike generating region (the axon hillock) is depolarized to threshold d. acetylcholine is released from the neuron s terminal e. the postsynaptic muscle fires an action potential 36. When blood is ejected from the left ventricle, where does it go? a. to the right atrium b. to the pulmonary circulation (to the lungs) c. to the systemic circulation (to the tissues) d. to the left atrium e. to right ventricle

6 Final Exam, 2008, Part 1 Shown to left are a series of photographs of a recently fertilized sea urchin egg. The letters A and B are placed near two structures that can be seen in all of frames except the last one. The scale bar gives time in seconds. The letter C indicates the structure just to the left of the letter. Questions 37 and 38 refer to this figure. 37. What are the structures marked A and B? a. The cortical vesicles b. The male (A) and female (B) pronuclei c. The female (A) and male (B) pronuclei, respectively d. Extra sperm due to a failure of the fast block to polyspermy e. The fertilization cone and the vitelline envelope 38. What is the structure marked C in final frame? a. The female pronucleus (haploid) b. The male pronucleus (haploid) c. The zygotic nucleus (haploid) d. The zygotic nucleus (diploid) e. The zygotic nucleus (tetraploid (4N)) 39. Color vision depends on the existence of a. color-coded bipolar cells for each wavelength b. the refraction of light into its component wavelengths, which impinge on different parts of the retina c. the graded response of the uniform photoreceptors to the different energy of the photons of various colors d. three different kinds of photoreceptor cells each containing a different form of retinal e. three different kinds of photoreceptor cells each containing a different form of the protein opsin 40. The barometric pressure on Pike s Peak is 53% of that at sea level. What is the partial pressure of O 2 in inspired, moistened air on Pike s Peak? a. 85 torr b. 75 torr c. 100 torr d. 95 torr e. 40 torr

7 Final Exam, 2008, Part Which of the following is not a neural crest derivative? a. The dorsal root ganglia b. The ganglia of the sympathetic nervous system c. The ganglia of the parasympathetic nervous system d. The motor neurons e. Pigment cells 42. Which asymmetric axis is already present in the unfertilized frog egg? a. The left-right axis b. The dorsal-ventral axis c. The rostral-caudal (head-tail) axis d. Both a and b e. Both b and c 43. The effect of ph on hemoglobin s affinity for O 2 : a. is increased ph increases the affinity b. is decreased ph increases the affinity c. ph has no effect on the affinity d. the effect of a given change in ph depends on where in the system it occurs e. the effect opposes the load of O 2 onto hemoglobin in the lungs 44. When the P CO2 of the arterial system exceeds 40 torr, the response of the respiratory system a. is to decrease metabolism in order to reduce CO 2 production b. is to cause inspired air to be enhanced in O 2 c. is to increase the rate of breathing d. is to acidify the blood so that more CO 2 can be carried as HCO 3 - e. is to decrease the rate of breathing 45. The rate of breathing in humans is controlled principally by a. cells that monitor the P CO2 in the blood b. cells that monitor the P O2 in the blood c. cells that monitor the degree of saturation of hemoglobin d. cells that monitor the degree of stretch of the alveoli e. cells that monitor the level of ammonia in the blood

29 Final Examination, In what tissues, indicated by the letters A-E, respectively in the diagram to the right, do the indicated action potentials occur? Conducting tissue refers collectively to the Bundle of His and the Purkinjie fibers. a. Ventricular myocardium, atrial myocardium, S A node, AV node, conducting tissue. b. SA node, atrial myocardium, AV node, conducting tissue, ventricular myocardium c. AV node, SA node, atrial myocardium, ventricular myocardium, conducting tissue. d. SA node, ventricular myocardium, AV node, conducting tissue, atria myocardium e. AV node, conducting tissue, SA node, atrial myocardium, ventricular myocardium 33. W hat is the special feature of the cells that produce the action potential shown in A in the diagram, compared to the cells producing the action potentials B and E? 2+ a. Their action potentials have a Ca component that is dependent on L-type Ca 2+ channels b. The resting potential of these cells spontaneously depolarizes following an action potential and generates another action potential when threshold is reached. c. They have the machinery to contract and expel blood from the atria. d. They are derived from neuronal tissue. e. They possess delayed rectifier K channels. 34. When blood is ejected from the left ventricle, where does it go immediately? a. to the right atrium b. to the pulmonary circulation (to the lungs) c. to the systemic circulation (to the tissues) d. to the left atrium e. to right ventricle 35. What one condition must be satisfied in order for water to move into a root hair cell from the soil? a. the osmolarity must be greater in the cell than in the soil b. the osmolarity must be greater in the soil than in the cell c. the hydrostatic pressure must be greater in the cell than in the soil d. the water potential must be greater in the cell than in the soil e. the water potential must be greater in soil than in the cell 11

Final Examination, 2007 36. In the diagram to the right, what is the point of control of the expression of the bicoid gene in the Drosophila egg? a. 1 b. 2 c. 3 d. 4 e. 5 37.

Wh at characteristic is shared by phytochrome and rhodopsin? a. They are both 7 TMD proteins b. They are both soluble proteins in the cytoplasm c.

30 Final Examination, In the diagram to the right, what is the point of control of the expression of the bicoid gene in the Drosophila egg? a. 1 b. 2 c. 3 d. 4 e In the diagram to the right, what is the point of control of expression of the hunchback gene by Bicoid protein in the Drosophila embryo? a. 1 b. 2 c. 3 d. 4 e Wh at characteristic is shared by phytochrome and rhodopsin? a. They are both 7 TMD proteins b. They are both soluble proteins in the cytoplasm c. They both consist of a protein coupled to a small, non-protein chromophore that actually absorbs light. d. They are both coupled to G proteins e. They are both involved in image formation 39. The rate of breathing in humans is controlled principally by a. cells that monitor the level of ammonia in the blood b. cells that monitor the P O2 in the blood c. cells that monitor the degree of saturation of hemoglobin d. cells that monitor the degree of stretch of the alveoli e. cells that monitor the P CO2 in the blood 12

31 Final Examination, 2007 All multiple choice questions are worth 2 points. Put your answers on the Scantron sheet. The structures labeled A in the electron micrograph below are found in the end of the axon of a vertebrate motor neuron. Questions 1-4 relate to this figure. A A 1. What are the structures labeled A, what do they contain, and what are they doing? a. Ribosomes containing mrna, engaging in protein synthesis b. Vesicles containing serotonin, fusing with the nuclear membrane. c. Vesicles containing calcium, releasing it into the synaptic cleft. d. Vesicles containing acetylcholine fusing with the neuronal plasma membrane. e. Vesicles derived from the SR containing norepinephrine fusing with the plasma membrane. 2. What is the structure identified with the white arrow? a. The plasma membrane of a skeletal muscle cell b. The membrane of the endoplasmic reticulum c. The cell wall d. The nuclear membrane e. The plasma membrane of a smooth muscle cell 3. What is the major component of the structure you identified in question 2? a. Calcium channels b. Rhodopsin c. muscarinic ACh receptors d. Adenylyl cyclase e. nicotinic ACh receptors 4

Final Examination, 2007 The following four questions relate to the diagram to the left. 28.

It is a secondary transport protein involved in moving VIP into the cell c.

What is the entity labeled 1? a. phospholipase C b. cgmp-specific phosphodiestase c. Guanylyl cyclase d.

32 Final Examination, 2007 The following four questions relate to the diagram to the left. 28. What is the nature of VIPR? a. It is an ion channel b. It is a secondary transport protein involved in moving VIP into the cell c. It is a 7 transmembrane domain (TMD) receptor d. It is a gap junction e. It is a Na/Ca exchanger 29. What is the entity labeled 1? a. phospholipase C b. cgmp-specific phosphodiestase c. Guanylyl cyclase d. Adenylyl cyclase e. Na-K ATPase 30. What are the entities labeled 2 and 3, respectively a. ATP, camp b. GTP, cgmp c. camp, ADP d. cgmp, GMP e. PIP 2, IP What is the entity labeled 4? a. Calmodulin b. Myosin light chain kinase c. Protein kinase A d. Amylase e. Ryanodyne 10

Final Examination, 2007 e. 5 μm Shown to the left are successive stages of the development of an animal embryo. The following four questions (16-19) refer to this figure. 16.

Human (Homo sapiens) 17. What are the white dots? a. multiple sperm, all of which but one will later be eliminated b. the cells of the blastula c. the cortical vesicles d.

33 Final Examination, 2007 e. 5 μm Shown to the left are successive stages of the development of an animal embryo. The following four questions (16-19) refer to this figure. 16. Wh at organism s early development is shown in the photographs? a. Sea urchin (Lytechinus pictus) b. Frog (Xenopus laevis) c. Fruit fly (Drosophila melanogaster) d. Chick (Gallus gallus) e. Human (Homo sapiens) 17. What are the white dots? a. multiple sperm, all of which but one will later be eliminated b. the cells of the blastula c. the cortical vesicles d. multiple nuclei resulting from mitoses without cell division e. mitochondria 18. What has occurred by frame 11? a. Gastrulation has begun b. Gastrulation has ended c. The excess sperm have been eliminated d. The neural tube has formed e. Th e multiple nuclei have moved to the surface and are being incorporated into cells, resulting in the formation of the cellular blastoderm. 19. What is the structure marked with an arrow at the bottom of frame 14? a. The blastopore b. The pole cells, which will become the germ cells and form the gametes c. The developing head d. The neural tube, which will become the spinal cord 7

34 Final Examination, After an action potential is fired in a motor neuron, there is a delay before another action potential can be initiated. Why? a. K + is depleted and it takes time for the Na-K pump to restore it b. The axon is filled with Na + and it takes time for the Na/K pump to eliminated it c. The Na + channels inactivate after they open, and they cannot open again for about 10 ms. d. Ca 2+ rises during the action potential and must be returned to basal levels e. The diffusion of neurotransmitters takes a few milliseconds 25. What is the basis of unidirectional transport of auxin in the stem cells of plants? a. The ph of the symplast and hypoplast are different b. The effect of gravity on transport c. Membrane potential gradients, with basal cells being negative compared to apical cells. d. The localization of IAA - transport proteins in the membrane at the basal ends of the cells e. The effect of unilateral light 26. What is the sequence of events in the fertilization of the sea urchin egg? a. acrosome reaction, Ca 2+ release, sperm-egg fusion, depolarization, cortical vesicle fusion b. sperm-egg fusion, acrosome reaction, Ca 2+ release, depolarization, cortical vesicle fusion c. acrosome reaction, sperm-egg fusion, depolarization, Ca 2+ release, cortical vesicle fusion 2+ d. sperm-egg fusion, acrosome reaction, depolarization, Ca release, vesicle fusion e. acrosome reaction, depolarization, Ca 2+ release, sperm-egg fusion, cortical vesicle fusion 27. The fast block to polyspermy in the sea urchin egg a. requires the cortical reaction b. depends on the elevation and hardening of the fertilization envelope 2+ c. depends on the entry of Ca from the seawater d. takes about 1 minute after fertilization to be established e. consists of the depolarization of the membrane potential 9

Final Exam 06-Part 1 Questions 36-38 refer to the figure below. 36. Which of the numbers identifies the structure that will produce the dorsal root ganglia? a. 2 b. 3 c. 4 d.12 e.13 37.

35 Final Exam 06-Part 1 Questions refer to the figure below. 36. Which of the numbers identifies the structure that will produce the dorsal root ganglia? a. 2 b. 3 c. 4 d.12 e Which of the numbers identifies the structure that will produce the motor neurons? a. 2 b. 3 c. 4 d.12 e Which of the numbers identifies the structure that induced the ectoderm to form neural plate and then a neural tube? a. 2 b. 3 c. 4 d.12 e The rate of breathing in humans is controlled principally by a. cells that monitor the level of bicarbonate in the blood b. cells that monitor the P O2 of the blood c. cells that monitor the degree of saturation of hemoglobin d. cells that monitor the degree of stretch of the alveoli e. cells that monitor the P CO2 in the blood 40. The function of gastrulation in all animals is a. to create notochord b. to create the gut tube c. to mark the dorsal side of the embryo d. to mark the ventral side of the embryo e. to induce the formation of the neural crest cells 11

Final Exam 06-Part 1 Shown below are photographs of three different dishes of lettuce seeds that were stored in the dark then were exposed to different regimes of light treatment.

36 Final Exam 06-Part 1 Shown below are photographs of three different dishes of lettuce seeds that were stored in the dark then were exposed to different regimes of light treatment. Questions 41 and 42 refer to this figure. 41. What was the last light treatment for each dish? a. A: red, B:far-red, C: blue b. A: far-red, B:red, C: far-red c. A: red, B:blue, C:far-red d. A: far-red, B: far-red, C: red e. A. blue, B: far-red, C: far-red 42. What molecule is responsible for perceiving the light signal? a. phytochrome, which consists of a non-protein chromophore attached to a protein and is active after it has absorbed far-red light. b. phytochrome, which consists of only a protein and is active after it has absorbed far-red light. c. phytochrome, which consists of only a non-protein chromophore and is active after it has absorbed red light. d. phytochrome, which consists of a non-protein chromophore attached to a protein and is active only after it has absorbed red light. e. rhodopsin, which consists of a non-protein chromophore attached to a protein and is active only after it absorbs blue light. 43. About how much O 2 is dissolved in arterial blood, in ml O 2 /L blood? To make the calculation simple, round the partial pressure of O 2 to one significant figure. You may find useful information on the first two pages. a. 0.3 b. 3 c. 30 d. 300 e

Final Exam 06-Part 1 The electron micrograph to the left shows the synapse between a motor neuron and a skeletal muscle. The following four questions (19-22) relate to this photograph.

37 Final Exam 06-Part 1 The electron micrograph to the left shows the synapse between a motor neuron and a skeletal muscle. The following four questions (19-22) relate to this photograph. Three distinct regions of the synapse are marked A, B, and C. The region B separates the other two regions. 19. What do the vesicles in the region marked A contain? a. Epinephrine b. Norepinephrine c. Ca 2+ d. Acetylcholine e. Impossible to say from the information given 20. What is the region marked B? a. The junctional fold (extracellular space) the gap between the presynaptic cell membrane and the postsynaptic cell membrane. b. The branched portion of the axon. c. Part of the T-tubule system d. The sarcoplasmic reticulum e. The axon hillock 21. W hat protein will be found in the plasma membrane enclosing region C? a. Muscarinic ACh receptors b. Rhodopsin c. Nicotinic ACh receptors d. Beta-adrenergic receptors e. Alpha-adrenergic receptors 22. What protein will be found in the plasma membrane enclosing region A? a. Muscarinic ACh receptors b. Nicotinic ACh receptors c. Voltage gated Cl - channels d. Voltage gated Ca 2+ channels e. G s 7

Final Exam 06-Part 1 All multiple choice questions are worth 2 points. Questions 1-5 refer to the diagram to the right. 1. What does the figure to the right show? a. Primary structure of a protein. b.

38 Final Exam 06-Part 1 All multiple choice questions are worth 2 points. Questions 1-5 refer to the diagram to the right. 1. What does the figure to the right show? a. Primary structure of a protein. b. Secondary structure of protein folded in an antiparallel-strand beta sheet. c. Secondary structure of a protein folded in a parallelstrand beta sheet. d. Secondary structure of a protein folded in an alpha helix e. Tertiary structure of a protein folded in a beta helix. 2. What is the physical basis of the force holding the strands together? a. Covalent bonds between the alpha carbon and amino nitrogen. b. Covalent bonds between carboxyl carbon and the amino nitrogen. c. Ionic bonds between the carboxyl oxygen and the amino nitrogen. d. Hydrogen bonds linking the amino nitrogen and the alpha carbon. e. Hydrogen bonds linking an amino nitrogen of one strand and a carboxyl oxygen of an adjacent strand. 3. Which of the numbers near the upper left of the diagram a. 1 b. 2 c. 3 d. 4 e What important component is left out of the diagram? a. The R-groups b. The phosphate ester linkages c. Fatty acids d. Nucleotides e. G-proteins indicates a peptide bond? 3

Nervous Tissue. Neurons Neural communication Nervous Systems

Nervous Tissue. Neurons Neural communication Nervous Systems Nervous Tissue Neurons Neural communication Nervous Systems What is the function of nervous tissue? Maintain homeostasis & respond to stimuli Sense & transmit information rapidly, to specific cells and