THIS IS NOT THE EXAM REVIEW SHEET! HELLO EVERYONE!!! These are questions from old exams that are relavent to Exam 4. I understand that there are many... however, these are an INCREDIBLY HELPFUL resource. I highly recommend running through all of them (maybe try answering 25-50 per day?) These questions are directly copied and pasted from a folder on blackboard posted by your professors.

Digestion, Transport and cardiovascular systems1. Which of the following does NOT require hemoglobin to deliver oxygen to the tissues. a. Earthworms *b. Insects c. Mammals d. Birds e. Amphibians

2. The vessels that return blood to the heart in a closed circulatory system are referred to as a. arteries. *b. veins. c. capillaries. d. sinuses. e. auxiliary hearts.

3. Which of the following is NOT a component of vertebrate blood? a. plasma. b. leukocytes. c. erythrocytes. d. platelets. *e. myoglobin.

4. Hemoglobin is more likely to release oxygen in metabolically active tissues because a. Metabolically active tissues produce more hemoglobin b. Metabolically active cells are nearer to capillaries *c. CO2 is an allosteric regulator of hemoglobin d. CO2 competes for heme binding e. Endorphins released by active tissues trigger oxygen release

5. In Tibetan populations living at high elevations, blood oxygen saturation levels have been correlated with a. Rates of pregnancy b. Rates of live birth c. Gestation period *d. Infant mortality e. Premature menopause

6. What allows many marine invertebrates (e.g. corals, jellyfish, sea anemones) to grow large in size even though they have only a gastrovascular cavity for circulation? *a. these organisms are only a few cells thick and can rely on diffusion to transport nutrients and oxygen throughout the body b. there are many branches within the gastrovascular cavity that directly transport nutrients and oxygen to various tissues c. a single, large heart provides enough pressure to deliver the blood throughout the entire body d. there are many openings to the gastrovascular cavity that allow nutrients and oxygen to be taken up from all directions

7. Why are respiratory and circulatory systems tightly coupled in organisms with closed circulatory systems? a. all cells in the body require nutrients, oxygen, and waste removal b. organisms with a low surface area:volume ratio cannot only rely on the simple diffusion of nutrients and gases to sustain life c. if these systems weren’t coupled, the blood pressure would be too low to circulate the blood throughout the entire body d. all of the above are true *e. only A and B are true

8. Cooperative binding of O2 by hemoglobin is physiologically important because a. it overcomes the limitation imposed by diffusion rates b. it allows saturation of blood with O2 at low partial pressure *c. it allows hemoglobin to readily give up most of its oxygen at sites of physiological activity d. it increases the O2 carrying capacity of blood e. it allows efficient exchange of O2 for CO2

9. Plant gas exchange occurs mainly through which of the following structures? a. companion cells b. trachea c. alveoli *d. stomata e. vessels

10. Consider the graphs shown. The center, blue line represents the O2 dissociation curve for adult hemoglobin. The line that represents fetal hemoglobin is

a. A because adult hemoglobin has a higher affinity than fetal Hb for O2*b. A because fetal hemoglobin has a higher affinity than adult Hb for O2c. B because adult hemoglobin has a higher affinity than fetal Hb for O2d. B because fetal hemoglobin has a higher affinity than adult Hb for O2

11. Which of the following factors contribute to water flow in xylem? *a. active transport in root cells and evapotranspiration through stomates b. root peristalsis and evapotranspiration through stomates c. active transport in root cells and capillary action d. capillary action and evapotranspiration through stomates e. active transport in root cells and capillary action

12. What is an advantage for insects to have an open circulatory system rather than a gastrovascular cavity? a. Insects are more efficient with a single heart. *b. Insects are terrestrial. c. Open circulatory systems allow high hemolymph pressures. d. An open circulatory system allows coupling of respiratory and circulatory systems.

13. What is an advantage for insects to have an open circulatory system rather than a gastrovascular cavity? *a. An open circulatory system provides for more metabolic dynamic range; the animal can respond to changes in energy demands. b. Insects don’t have open circulatory systems. c. Open circulatory systems allow high hemolymph pressures. d. An open circulatory system allows coupling of respiratory and circulatory systems.

14. Which of the following statements about amphibian and mammalian circulatory systems is true?*a. Pulmonary circulation occurs at reduced blood pressure.b. Amphibians have 4 heart chambers similar to mammals.c. Oxygen and carbon dioxide exchange only occursin the lungs and skin.d. All of the above are true.e. None of the above are true.

15. Which of the following statements is NOT true about a capillary bed?a. The drop in blood pressure across the capillary is partially due to fluid loss.

*b. Large proteins diffuse out of the vasculature on the arteriole side and intothe vasculature on the on the venule side.c. The lymphatic system collects water and solutes that are not picked up by the venules.d. The addition of CO2 to the blood decreases the pH of the blood.e. None of the above. All of the above statements are true.

16. Which of the following statements about the blood vessels shown in this figure is NOT true?a. The endothelium provides the conduit for the transport of the blood while allowing small molecules to diffuse into and out of the circulatory system.b. The elastic layers of the large arteries and large veins help to moderate blood pressure fluctuations during and between heart contractions.c. Fenestrated capillaries allow more fluid loss than continuous capillaries.d. The smooth muscle cells contribute to vasodilation and vasoconstriction.*e. None of the above. All of the statements are true.

17. Based on what is shown in these oxygen binding curves, which of the following is true?a. At lower temperatures hemoglobin has a lower affinity for oxygen.b. Elevated temperatures increase hemoglobin’s affinity for oxygen.c. Increasing exertion at higher altitudes increases oxygen binding to hemoglobin.d. All of the above are true.*e. None of the above are true.

18. This question focuses on long-distance transport in the xylem. Which of the following is NOT true? *a. Flow of fluids through xylem is not mediated by pressure differences. b. Cohesion-tension theory relies on the polar nature of water molecules. c. Transpiration involves evaporative loss of water. d. None of the above. All of these statements are true.

(No figure...)

19. The figure above is from your textbook. Which of the following statements is NOT true?a. Osmosis is a key component of water flow between the xylem and the phloem.*b. Developing fruit represents a sucrose source.c. Sink cells uptake sucrose by means of plasmodesmata and concentration gradients.d. Source cells have higher osmotic pressure than sink cells.e. None of the above. All of these statements are true.

20. Stomatal opening is driven by…. a. Water efflux from the guard cells driven by osmosis due to lower extracellular ion concentrations. *b. Water influx via osmosis into the guard cells due to pumping of ions and cotransport of sugars into the guard cells.

21. What energy sources drive water transport in the xylem? a. Gravity and photosynthesis b. Stomates and soil pressure c. Gas exchange and xylem vessels *d. Sunlight and ATP

22. Where to roots get their sugars? a. From photosynthesis in the root hairs *b. Via the phloem from the leaves c. By active transport from the soil

23. Which of the following is NOT an important aspect contributing to water transport through the xylem? a. cohesion among H2O molecules due to hydrogen bonding

*b. osmosis due to sugar produced in photosynthesizing leaves c. active transport of mineral ions from the soil into roots d. transpirational H2O loss from leaves e. continuous tubes created by dead vessel and tracheid cells

24. Consider the graphs shown. The center, blue line represents the O2 dissociation curve for hemoglobin under normal physiological conditions. The line that represents hemoglobin (Hb) in tissues undergoing intense metabolic demands is

a. A because CO2, low pH and high temperatures increase the affinity of Hb for O2 b. A because CO2, low pH and high temperatures decrease the affinity of Hb for O2 c. B because CO2, low pH and high temperatures increase the affinity of Hb for O2 *d. B because CO2, low pH and high temperatures decrease the affinity of Hb for O2

Nervous System25. Which of the following cells or structures is part of the peripheral nervous system? a. an interneuron in your brain b. the spinal cord *c. the cell body of a sensory neuron on your tongue d. the hypothalamus e. an intestinal epithelial cell

26. A rattlesnake just tried to bite you. Your pulse is racing and you notice your pupils are wide open when you step into your car and look

in your rearview mirror. What part of your autonomic nervous system is activated? a. Myelencephalon b. Neocortex *c. Sympathetic d. Peripheral e. Parasympathetic

27. As an action potential moves along an axon, the membrane potential changes.  Which of the following best describes the molecular mechanisms that cause these changes in membrane potential? a. Action potentials are mediated by changes in transcription.  Different gene expression patterns cause different membrane potentials. b. As an electron moves along the length of the axon, it transiently heats the membrane, and this changes the membrane potential. c. Action potentials are mediated by calcium-mediated exocytosis of neurotransmitters.  When the vesicles fuse with the membrane, this changes the membrane potential. d. Sodium and potassium ions speed along the length of the axonal cytoplasm, and this changes the local membrane potential as the action potential passes through. *e. Action potentials are mediated by voltage-gated sodium and potassium channels, and diffusion of ions across the membrane cause the changes in membrane potential.

28. The location for chemical communication between a neuron and a target cell is called the a. motor neuron *b. synaptic cleft c. oligodendrocyte d. acetylcholine e. axon hillock

29. In a neuron, the nucleus is located in the a. dendritic region. b. axon hillock. c. axon. *d. cell body. e. axon terminals.

30. In a neuron, the nucleus is located in the a. dendritic region. b. axon hillock. c. axon.

*d. soma. e. axon terminals. 31. In general, the input processes of a neuron in the central nervous system are referred to as a. axons b. synaptic cleft c. neuromuscular junction *d. dendrites e. synaptic terminals

32. Which of the terms below best describes neurons that make local connections between neurons in the brain? a. motor neurons b. sensory neurons *c. interneurons d. hub neurons e. transit neurons

33. Which term below best describes neurons that are responsible for stimulating contraction of muscles in your leg? *a. motor neurons b. sensory neurons c. interneurons d. hub neurons e. transit neurons

34. Which term below best describes neurons that are responsible for sensing pressure in your skin? a. motor neurons *b. sensory neurons c. interneurons d. hub neurons e. transit neurons

35. Which is NOT a factor that contributes to the resting potential? a. Ion specific channels allowing passive movement of ions b. Na+/K+ -ATPase *c. Binding of neurotransmitters to ligand-gated ion channels d. Negatively charged molecules such as proteins that are more abundant inside the cell e. All the above contribute to the resting potential

36. The inside of a plasma membrane of a neuronal axon generally has a negative resting

potential relative to the outside of the cell. 37. 37. Which of the following changes would result in depolarization of the membrane? *a. Na+ entering the cell b. K+ leaving the cell c. Retraction of the axon d. Neurotransmitter release from the cell

38. In the two cellular compartments shown above, K+ is moving across the membrane from the left to the right. Why is K+ moving from the left to the right?*a. K+ is moving down its concentration gradientb. K+ is moving down its electrical gradientc. Cl- is attracting K+

d. K+ is moving because the membrane is impermeable to Cl-

39. If the K+ channel closed, so the ions were trapped in the compartments as shown above, what would the voltage of the right side of the cell be in relation to the left?*a. Equalb. Negativec. Positived. Cannot be determined

40. The response of a postsynaptic cell is determined by:a. A. The type of neurotransmitter released at the synapse.b. B. The type of receptors the postsynaptic cell has.c. C. The number of Na+ channels in the postsynaptic membraned. D. The number of K+ channels in the postsynaptic membrane.*e. All of the abovef. A and C only

41. How does a sensory system provide information about the intensity of a stimulus? a. The larger the action potential, the larger the stimulus. b. by the release of both dopamine and acetylcholine the cell senses a larger stimulus c. More chloride channels close, thereby creating greater transmitter uptake. *d. Via action potentials, the frequency of action potential firing is related to the intensity of the stimulus.

42. How does a sensory system provide information about the intensity of a stimulus? a. The higher the threshold, the larger the stimulus. b. by the release of both dopamine and acetylcholine the cell senses a larger stimulus c. More chloride channels close, thereby creating greater transmitter uptake. *d. Via action potentials, the frequency of action potential firing is related to the intensity of the stimulus.

43. The process whereby incoming sensory information is converted to an electrical signal is known as: a. threshold potential b. an action potential c. perception *d. sensory transduction e. reception

44. As a sensory neuron in your skin is lightly stimulated, a receptor potential is generated. However, the membrane potential change in this sensory neuron does not reach threshold. Most

likely, you perceived that stimulus as a sensation of: a. pain b. heat c. cold d. intense pressure *e. I did not perceive that, since the threshold potential was not achieved, I could not perceive that sensation.

45. What type of stimulus is responsible for activating your cones and rods? a. mechanical energy b. thermal energy c. chemical energy *d. electromagnetic energy e. pressure energy

46. Touch receptors in your skin are activated by what type of stimulus? a. electromagnetic energy b. nuclear energy *c. mechanical energy d. photonic energy e. sonic energy

47. How do neurons establish differential concentrations of ions inside and outside the cell? *a. active transport b. osmosis c. simple diffusion d. facilitated diffusion

48 . What factors contribute to the resting potential in a nerve cell? a. sodium-potassium pumps, ligand-gated ion channels, negatively charged molecules (i.e. proteins) are more abundant inside the cells b. sodium-potassium pumps, ion specific channels, positively charged molecules (i.e. proteins) are more abundant inside the cells *c. sodium-potassium pumps, ion specific channels, negatively charged molecules (i.e. proteins) are more abundant inside the cells d. sodium-potassium pumps, ion specific channels, positively charged molecules (i.e. proteins) are more abundant outside the cells

49. Initiation of an action potential involves: a. membrane hyperpolarization *b. Sodium channel opening c. Potassium channel opening d. refractory period e. Potassium channel closing

50. In an action potential, the return to the resting potential involves:a. A. Cl- channel inactivationb. B. Na+ channel inactivationc. C. Na+ channel openingd. D. K+ channel closinge. E. K+ channel openingf. A, B and Dg. B and D*h. B and E

51. Which of the following features allow neurons to rapidly conduct action potentials to muscles in your foot?(1) myelination of the axon provided by oligodendrocytes(2) a large diameter axon(3) a small, narrow diameter axon(4) myelination of the axon provided by Schwann cellsa. 1 and 2b. 1 and 3*c. 2 and 4d. 3 and 4

52. How does our nervous system organize information about our sensory environment? a. by opening more voltage-gated and ligand-gated ion channels *b. by forming topographic representations of that particular sensory information c. by relaying information using interneurons through the spinal cord d. by increasing the amplitude of the receptor potentials

53. In some plants electrical signals can travel from cell to cell via: a. electrical synapses b. chemical synapses c. chloroplast junctions *d. plasmodesmata

54. In some plants electrical signals can travel from cell to cell via: a. electrical synapses b. tight junctions c. chloroplast synapses *d. plasmodesmata

55. In some plants electrical signals can travel from cell to cell via: a. gap junctions b. ligand-gated ion channels *c. plasmodesmata d. chloroplasts 56. Why are squid giant axons used in neuroscience research?a. their action potentials are stronger and hence easier to detect.b. they do not have any refractory period and so can be used repeatedly.*c. they have a large diameter and so can be easily impaled by electrodes to record their membrane potential.d. because squid live in saltwater their axons can be easily kept alive in a saline solution.

57. In a resting neuron, the concentration of potassium ions (K+) is: *a. higher inside the cell than outside of the cell b. lower inside the cell than outside of the cell c. the same inside and outside the cell d. it varies with different neurons

58. In a resting neuron, the concentration of sodium ions (Na+) is: a. higher inside the cell than outside of the cell *b. lower inside the cell than outside of the cell c. the same inside and outside the cell d. it varies with different neurons

59.Which of the following factors contribute to the resting potential in a nerve cell? a. Ion specific channels that allow passive movement of ions b. An ATPase-driven sodium-potassium ion pump. c. Negatively charged molecules such as proteins that are more abundant inside the cell. *d. All the above contribute to the resting potential

60. Which is involved in repolarizing a neuronal membrane following an action potential?a. Vesicle fusionb. Ligand gated channels*c. Opening K+ channels

d. Opening Na+ channels

61. Which is involved in depolarizing a neuronal membrane during an action potential?a. Vesicle fusionb. Ligand gated channelsc. Opening K+ channels

*d. Opening Na+ channels

62. In an action potential, the return to the resting potential involves: a. Na+ channel opening and K+ channel closing b. Ca+ binds to vessicles to induce exocytosis *c. Na+ channel inactivation and K+ channel opening d. None of the above.

63. What do potassium ions (K+) do during an action potential? a. they exit the neuron via vesicle exocytosis. b. they bind to vesicles to induce exocytosis. *c. they exit the neuron via voltage-gated potassium channels. d. they exit the neuron via the sodium-potassium pump.

64.What do sodium ions (Na+) do during an action potential? a. they enter the neuron via sodium-potassium pumps and depolarize the membrane. *b. they exit the neuron through voltage-gated sodium channels and hyperpolarize the membrane. c. they enter the neuron via voltage-gated sodium channels and depolarize the membrane. d. they enter the synaptic cleft via exocytosis.

65.Which of the following statements about graded potentials in neuronal signaling is NOT TRUE? a. They sometimes involve membrane hyperpolarization

b. They sometimes involve membrane depolarization c. They vary in amplitude according to the strength of a stimulus d. They determine whether threshold potential is reached for initiating an action potential *e. All of the above statements are true

66. Action potentials are normally conducted in just one direction on an axon becausea. voltage gates prevent back conductance*b. Na+ channels are inactivated during the refractory periodc. myelin sheaths provide directional guidanced. there is an electrochemical gradient toward the end of the axone. all of the above

67. If you artificially depolarize the membrane to start an action potential in the middle of an axon, what will happen? a. Nothing. Action potentials can only initiate at the axon hillock. b. The action potential will be conducted in just one direction (toward the synapse). *c. The action potential will travel in both directions. d. The neuron will die.

68. Myelination of axons is important because a. it slows the speed of neural impulse conductance b. it enhances neurotransmitter sensitivity *c. it enhances the speed of neural impulse conductance d. it increases the strength of action potentials e. it lowers threshold potential

69. Individuals with multiple sclerosis have longer reaction times to various stimuli. This can be explained by the following: a. They have a defect in voltage-gated sodium channels which are required to initiate action potentials. *b. They have degradation of myelin sheaths resulting in slower conductance of signals. c. They have a defect in neurotransmitter release, so it takes a longer time to transmit sufficient numbers of graded potentials to the post-synaptic cell.

d. They have abnormal ladder-like connections in their cerebral cortex, resulting in impaired decision-making ability.

70. Which of the following statements about myelin sheaths on axons is NOT TRUE *a. They are secreted by the nodes of Ranvier b. They are composed of layers of glial cell membranes wrapped around the axon c. They produce saltatory neural signal conductance d. They increase the speed of neural signal conductance e. All these statements are true

71. A neurotransmitter is*a. a signaling molecule that influences membrane potential of a post-synaptic cellb. an electro-chemical impulsec. a type of glial celld. a type of membrane vesiclee. a gap junction that connects two neurons

72. A neurotransmitter*a. is a signaling molecule that influences membrane potential of a post-synaptic cellb. is an axonc. is an electrical impulsed. is a type of membrane vesiclee. is a type of efferent motor neuron

73. Postsynaptic cells a. Receive signals by endocytosis b. Always respond to signals with an action potential c. Are always neurons *d. Often contain neurotransmitter receptors e. Are connected to presynaptic cells by gap junctions

74. In neural signaling, ligand-gated ion channels *a. are ion channels that are opened (or closed) in response to binding a neurotransmitter b. are gap junctions that allow Na+ transport across a synapse c. are voltage-gated Ca++ channels that trigger neurotransmitter uptake d. are sensory neurons that detect electromagnetic stimuli

e. direct chemotaxis of axons to guide neural connections during development

75. Presynaptic release of neurotransmitter a. Is triggered by a graded potential b. Occurs through gap junctions c. Requires electrical synapses d. Occurs via endocytosis *e. Occurs via exocytosis

76. Predict the effect of a chemical that blocked voltage-dependent Calcium ion channels at the synaptic ending of an axon. a. The axon could not generate an action potential. b. The cell would continually release neurotransmitter via vesicle exocytosis. *c. The calcium channels would not open, and this would inhibit neurotransmitter release. d. It would not have an effect. Only sodium and potassium channels are voltage-gated; Calcium channels are ligand-gated.

77. A neurotoxin that stimulated acetylcholine release would most likely cause a. numbness b. hallucinations c. ATP depletion *d. muscle cramping e. dizziness

78. The peripheral nervous systema. Controls cognition*b. Provides sensory inputc. Commands the central nervous systemd. All of the above

79. Approximately how long does a single action potential take? *a. 3 milliseconds b. 30 microseconds c. 180 milliseconds d. 250 milliseconds

80. Approximately what is the normal resting potential of a neuron? a. -100 mV *b. -70 mV c. -30 mV d. 30 mV

81. Approximately how many neurons do you have in your brain? a. 100 million b. 1 billion c. 10 billion *d. 100 billion

82. Which lobe of the brain is most responsible for vision? a. Parietal lobe *b. Occipital lobe c. Temporal lobe d. Frontal lobe

83. Which lobe of the brain is most responsible for conscious thought? a. Parietal lobe b. Occipital lobe c. Temporal lobe *d. Frontal lobe

84. Which of the following is most highly developed in human brains compared to other mammals? a. Medulla oblongata b. Hypothalmus *c. Cerebral cortex d. Midbrain e. Hindbrain

85. How does a sensory system provide information about the intensity of a stimulus? *a. Sensory receptors produce different frequency of action potentials depending on intensity of a stimulus b. Sensory receptors produce different amplitude of action potentials depending on intensity of a stimulus c. By the release of both dopamine and acetylcholine the cell senses a larger stimulus d. More chloride channels close, thereby creating greater transmitter uptake.

86. How does a sensory system provide information about the intensity of a stimulus? a. The stronger the action potential, the more intense is the stimulus. b. by the release of both dopamine and acetylcholine the cell senses a larger stimulus c. More chloride channels close, thereby creating greater transmitter uptake.

*d. The frequency of action potential firing is related to the intensity of the stimulus.

87. One type of mechanosensors a. Responds to chemical pheromones released by scent glands. b. Detects specific wavelengths of light and transmits action potentials to the occipital lobe via the optic nerve. c. Produces different amplitude of action potentials depending on intensity of a stimulus *d. Contain stretch-induced ion channels that lead to membrane depolarization when cells are deformed.

88. We detect different auditory tones because different sound frequencies a. cause different action potential amplitudes in auditory neurons b. are processed by different auditory ganglia in the ear lobe c. travel at different speeds through the vestibular fluids in the ear *d. vibrate different parts of the cochlea, which are detected by different mechanosensory cells.

89. We detect motion and position because a. statoliths in our ears cause different action potential frequencies in statitory neurons *b. hair sensory cells detect movements of the vestibular fluids in our ears c. gravity pulls hairs on sensory cells downward d. proprioceptors emit neurotransmitters in the direction of gravity e. ossicles vibrate different parts of the cochlea in response to movement and gravity, which is detected by different mechanosensors

90. Invertebrates use the following system to detect gravity and maintain body orientation *a. A sphere of sensory hair cells contains a statolith that moves in response to gravity. b. hair sensory cells detect movements of vestibular fluids in the semicircular canals. c. gravity pulls hairs on sensory cells downward d. proprioceptors emit neurotransmitters in the direction of gravity e. ossicles vibrate different parts of the cochlea in response to movement and gravity, which is detected by different mechanosensors

91. Some plants respond to touch by a. transmitting action potentials from cell to cell via plasmodesmata b. opening ion channels in specialized cells c. Ions and water flow out of specialized cells, resulting in cell flattening and leaf movement. *d. All of the above.

92. Folding of Mimosa (sensitive plant) leaves in response to touch *a. is triggered by an action potential b. is controlled by hormones c. is controlled by neurotransmitters d. is a stomatal response

93. In neural signaling, ionotropic receptors *a. are ion channels that are opened (or closed) in response to binding a neurotransmitter b. are gap junctions that allow Na+ transport across a synapse c. are voltage-gated Ca++ channels that trigger neurotransmitter uptake d. are sensory neurons that detect electromagnetic stimuli e. direct chemotaxis of axons to guide neural connections during development

94. In a resting neuron, the negative charge inside the cell results from a. Of the energy provided by ATP b. Ion-selective channels allow diffusion of K+ c. The diffusion (concentration) gradient of K+ions opposes the electrical gradient d. The cell membrane is impermeable to Na+ or Cl-ions. e. 2 & 3 *f. All of the above  95. Sensory receptors a. All connect to the same sensory center in the brain b. Interpret the quality of input stimuli *c. Produce different frequency of action potentials depending on intensity of a stimulus d. Produce different amplitude of action potentials depending on intensity of a stimulus e. All of the above

96. The figure shows traces from action potentials of normal neurons (control) and neurons treated with alpha-dendrotoxin (α-DTX). Dendrotoxin most likely affects

a. active transport b. neurotransmitter release c. Ca++ channel opening d. Na+ channel opening *e. K+ channel opening

Muscle/locomotion97. Which of the following is true of the arrangement of actin and myosin filaments within a myofibril? a. Thin filaments extend the entire way across the sarcomere b. Thick filaments are attached to the end walls of the sarcomere *c. Thin filaments are attached to the end walls of the sarcomere d. Thick filaments run towards the center from each side of the sarcomere, leaving a gap in the middle e. Thin filaments traverse the sarcomere center but do not reach the end walls

98. After ACh binds to the receptors in the muscle fiber plasma membrane, Na+ floods into the muscle fiber. Why? a. Na+ signals for the muscle fiber to quit binding to ACh b. Na+ is a part of the ACh molecule that broke off inside the cell c. Na+ is so small that it is always diffusing across the cell membrane *d. Na+ depolarizes the cell membrane to initiate an action potential

e. Na+ signals for ACh to be removed from the synaptic cleft by the enzyme acetylcholinesterase

99. Hydrostatic skeleton is one in which a. A hard, exterior coating is used b. A system of hard plates is used *c. Fluid under pressure is used d. Skeletal pieces are embedded in a gelatin-like material

100. Each skeletal muscle cell constitutes a single a. motor unit b. sarcolemma c. myofibril d. sarcomere *e. muscle fiber

101. Which of the following is a common neurotransmitter found invertebrate neuromuscular junctions? a. Serotonin b. Glutamate c. Dopamine *d. Acetylcholine e. Epinephrine

102. Which of the following is a common neurotransmitter found in vertebrate neuromuscular junctions? *a. Acetylcholine b. Serotonin c. Glutamate d. Dopamine e. Epinephrine

103. Cross-bridges form between _____ and _____ during muscular contraction. *a. actin, myosin b. actin, tropomyosin c. myosin, troponin d. myosin, tropomyosin e. troponin, calmodulin

104. Neuromuscular junctions involve a. a neural dendrite, a gap junction, and the sarcoplasmic reticulum b. a synapse, a myofibril, and troponin

*c. an axon terminal, acetylcholine, and ligand gated ion channels d. a synaptic cleft, norepinephrine, and an axon terminal e. an electrical synapse, a node of Ranvier, and acetylcholine 105. An action potential in a muscle cell *a. triggers Ca++ release from the sarcoplasmic reticulum b. is propagated through voltage gated Ca++ channels c. is initiated by myosin binding to actin filaments d. causes release of acetylcholine e. all of the above

106. What would happen to a myofibril if ATP were depleted from a muscle cell? *a. Myosin could not release from actin b. Myosin could not bind actin c. Myosin could not perform a power stroke d. Actin would depolymerize e. Myosin could not hydrolyze

107. When during a muscle contraction sequence is ATP hydrolyzed to provide power? a. cross bridge formation (binding) b. power stroke c. Detachment of myosin from actin *d. Reactivation of myosin heads e. to remove tropomyosin from the binding sites on actin

108. Calcium in skeletal muscle cells a. Creates an action potential b. Binds myosin c. Binds actin *d. Regulates availability of myosin binding sites on actin e. Is stored in the symplastic infundibulum

Reproduction109. A pollen grain a. is a diploid organism b. is a female gametophyte c. contains an egg cell *d. produces 2 sperm cells e. None of the above

110. In plant reproduction, alternation of generations refers to alternating between a. male and female b. embryo and endosperm *c. haploid and diploid d. epiphyte and halophyte e. monocot and dicot 111. In mammals, male sex characteristics are determined by all the following EXCEPT a. Having a Y chromosome *b. Having only one X chromosome c. Testes determining factor d. Testosterone levels  112. Which of the following is NOT true for both male and female mammalian gametogenesis? *a. One primary cell produces four mature gametes. b. Germ line cells multiply by mitosis. c. Primary cells (spermatocytes and oocytes) are diploid. d. Gametes are formed by meiosis. e. Gametes develop in the gonads.  113. In mammalian females, germ cells (oocytes) are a. not produced until puberty. *b. nearly all produced in the fetus. c. fully mature gametes at birth. d. produced in the embryo sac. e. arrested in mitosis until puberty.

114. Which of the following is NOT TRUE of the placenta a. It functions in exchange of gases, nutrients and wastes between mother and fetus b. It develops from maternal and fetal tissue c. The fetal portion (chorion) has chorionic villi providing a large surface area for exchange *d. Blood of the mother and fetus mix e. It transports drugs and alcohol from mother to fetus

115. In mammals, the primary signal of a successful fertilization  is *a. the uterus produces chorionic gonadotropin which signals the corpus luteum in the ovary b. the follicle produces estrogen, which signals the corpus luteum to decrease progesterone

c. the corpus luteum in the ovary produces estrodiol, which signals implantation in the uterus d. the completion of meiosis II triggers estrogen and progesterone, which signal the uterus e. mechanosensors in the uterine wall are are depolarized by implantation, triggering an action potential115. Females produce eggs. Which of the following is NOT a feature of meiosis in most female germlines?  a. Chromosome number is reduced from 4 to 1. b. Unequal cytokinesis results in a single larger cell with most of the cytoplasm. *c. The diploid oocyte is the final product. d. Polar bodies contribute to reduction of chromosome number. e. None.  All of the above statements are true.

116. Which of the following is NOT a form of asexual reproduction? a. Mitosis b. Budding *c. Gender switching in fish d. Regeneration e. Parthenogenesis 117. Which of the following is NOT an advantage of asexual reproduction? a. Able to reproduce even if isolated b. Able to reproduce rapidly c. Can generate large numbers of offspring *d. Greater genetic variation e. All of the above f. None of the above

118. The table above is derived from the Komodo dragon parthenogenesis article. What aspects of this data set support the hypothesis that Sungai’s offspring are the result of sexual reproduction?a. All of the offspring are homozygous at each of the microsatellite loci analyzed.b. The absence of the 133 microsatellite marker in the offspring at the K06 locus.

c. All of the microsatellite markers of the offspring are found in Sungai’s DNA.*d. None. All of the above statements support the hypothesis that Sungai’s offspring are the result of parthenogenesis.

119. Sex determination in Komodo dragons is based on a system where females are WZ (dissimilar chromosomes) and males are ZZ (similar chromosomes).  Based on the observations about parthenogenesis in Komodo dragons, what sex were the offspring produced by parthenogenesis? a. Female *b. Male c. The offspring could be either male or female. d. The offspring would be of indeterminate sex.

120. The figure above is from the “Mice without a Father” article.  Based on what is shown above and what we discussed in class, which of the following is NOTtrue?*a. Epigenetics does not affect gene expression.b. The maternally contributed genes are necessary for normal development of the embryo.c. Gene expression from the paternal genome is necessary for extraembryonic tissue development.

121.The figure above is from the “Mice without a Father” article.  The differentially methylated domain (DMD-Illustrated by the green bar if it is methylated (CH3).) is key to this epigenetic gene regulation.  Which of the

following is the result if this region is NOT methylated (A nonmethlyated DMD is illustrated by the presence of the blue bar.)?a. The enhancers activate the expression of Igf2.*b. The enhancers activate the expression of H19.c. The enhancers fail to activate the expression of either Igf2 or H19.

122. Based on what we discussed about mammalian imprinting, which of the following is a characteristic of epigenetic gene regulation?

a. Epigenetic DNA methylationb. is the same between homologous chromosomes

in early mammalian embryos. b. Epigenetic imprinting results in the removal of genes from the chromosomes. *c. Epigenetic DNA methylation can result in genes not being transcribed. 123. Which of the following is a characteristic of sexual reproduction? *a. The embryo is usually the result of the fusion of gametes from different genetic backgrounds. b. The embryo is usually the result of the fusion of diploid gametes from two different parents. c. The species is less able to adapt to changes in the environment due to less genetic diversity within the population. d. The genome is less likely to retain deleterious mutations in critical genes.

124. Recombination occurs… a. as gametes are in the final stages of maturation. b. during the separation of homologous chromosomes in mitosis. *c. during the separation of homologous chromosomes in meiosis I. d. as the sister chromatids separate during mitosis.

125. of the following is NOT a mechanism for sex determination? a. Temperature b. The X chromosome to autosomal chromosome ratio. c. Sex determining factors on sex chromosomes. *d. None. All of the above are mechanisms for sex determination.

126. Which of the following is a characteristic of asexual reproduction? a. It is limited to invertebrates. b. It allows for the maintenance of greater genetic diversity. *c. It allows for the maintenance of successful genotypes. d. It requires meiotic cell division.

127. In plants, ….. a. 1n individuals produce gametes via meiosis. b. 2n individuals produce gametes via mitosis. *c. 1n individuals produce gametes via mitosis. d. 2n individuals produce gametes via meiosis.

128. Which of the following is a characteristic of pollen and stigma self-incompatibility? a. It prevents the pollen and stigma from adhering to each other. b. It allows plants to self fertilize *c. It inhibits pollen tube growth. d. It reduces genetic diversity.

129. Double fertilization in flowering plants… *a. results in the formation of a 3n endosperm. b. allows for plants to self fertilize. c. is a form of parthenogenesis. d. is a system that improves fertility since only one of the sperm needs to successfully fertilize the egg.

130. In the alternation of generations in flowering plant lifecycles, a. the haploid phase is often free living. *b. the diploid phase is dominant. c. the diploid phase produces the gametes. d. the endosperm is haploid.

131. Based on the feature investigation about plant in vitro fertilization, which of the following statements is NOT true about plant in vitro fertilization? a. In vitro fertilization was not reported until 1993 because of the difficulty of isolating sperm and egg cells in plants. *b. In vitro pollination and in vitro fertilization are equivalent. c. The successful fertilization was demonstrated by the expression of paternal- and maternal-derived markers.

d. The fusion of egg and sperm cells was achieved by electric shock.

132. Parthenogenic offspring have been noted in all of the following except: a. lizards b. sharks *c. mammals

d. bees

 133. The figure above is from the “Mice without a Father” article. Based on what is shown above and what we discussed in class, which of the following is NOT true?*a. The expression of paternal genes is not required for normal development.b. The maternally contributed genes are necessary for normal development of the embryo.c. Gene expression from the paternal genome is necessary for extraembryonic tissue development.

134. Which of the following outcomes would result if parthenogenesis were the result of either failure of cytokinesis in meiosis II or fusion of the oocyte and the second polar body?

a. XX and XXb. XXc. XX*d. XX and XXe. XX f. XX

Disease135. Which of the following is the best definition of disease? a. Any condition that leads to cell death. b. Any condition caused by infection with pathogens, such as bacteria or viruses. c. Any condition caused by genetic mutations or inheritance of defective genes. *d. Any condition that impairs normal function. e. None of the above.

136. Which of the following is NOT a characteristic of cancer a. Cancer cells divide uncontrollably. b. Cancer is a malignant disease, meaning that it progressively becomes worse. *c. Cancer is caused by one single mutation that results in increased cell division. d. Cancer is relatively rare at the cellular level, but common among organisms. e. Cancer can metastasize, spreading to other tissues.

137. Activated p53 halts the cell cycle and promotes DNA repair, while inactivated p53 is quickly broken down. p53 is activated in the presence of DNA damage. In the scenario depicted, the p53 gene is mutated and therefore the p53 protein can never be activated. Will this cell divide?a. Yes, because the mutated p53 will induce the expression of genes that promote cell division.*b. Yes, because the mutated p53 cannot induce expression of genes that halt the cell cycle.

c. No, because the mutated p53 will inhibit proteins that promote cell division.d. No, because the mutated p53 will be detected by the cell, and the cell will not survive.

138. Radiation therapy for cancer induces severe DNA damage. Which of the following cancer cells is this therapy LEAST likely to work on? a. Cancer cells that already have many mutations. b. Cancer cells that have gain-of-function mutations in a growth factor receptor, such that the receptor is always activated. *c. Cancer cells that have loss-of-function mutations in p53, such that p53 cannot be activated. d. Cancer cells that still retain “self” signals and can evade the immune system.

139. Consider a genetic mutation in a gene for a death signal receptor, “Y”. In this mutation, a stop codon has been inserted in the middle of the coding region of the gene. What is the most likely outcome? *a. Only part of protein “Y” will be translated, and the resulting protein will probably not be functional. b. RNA polymerase will detect the mutation and the gene will not be transcribed. c. The ribosomes will detect the mutation in the mRNA and translation will not occur. d. The ribosomes will recognize the base pair mismatch in the mRNA and correct the mutation.

140. What is genomic instability? a. A mutation in a gene for a protein that detects DNA damage. b. Any mutation that deletes or copies a large chunk of a chromosome. c. When chromosomes break up into many smaller chromosomes. *d. The rapid accumulation of mutations over time.

141. Which of the following cellular processes in cancer cells do NOT directly promote metastasis? a. Migration b. Maintaining survival signals

c. Cell division *d. Apoptosis

142. Consider a gene encoding for a protein important for growth factor signaling. When mutated, this protein becomes constantly active. This gene is most likely a: a. Tumor suppressor b. Tumor promoter *c. Proto-oncogene d. Carcinogen

143. Imagine a mutated form of the epidermal growth factor (EGF) receptor. This receptor now signals even when there is no EGF bound to it. What is the result?*a. The signal cascade will always be active, so the cell will always behave as if it is receiving growth signals and will divide.b. Since the cell cannot bind to EGF, it cannot receive growth signals and will not divide.c. The signal transduction cascade will always be active, but because there is no EGF the cell will not divide.d. The cell will die because the signal transduction cascade produces toxic byproducts.

144. Which of the following is most likely to be tumor suppressor? a. a gene that increases cell proliferation. b. a gene which codes a fluorescent protein. *c. a gene important for repairing DNA damage. d. a gene that enables adaptation to hypoxia (low oxygen). e. a gene that stimulates angiogenesis (formation of new blood vessels).

145. The acquired immune system is very effective. Why?

*a. The cells of the acquired immune system recognize very specific antigens, so only particular pathogens or abnormal cells are targeted. b. The cells of the acquired immune system can recognize very general “non-self” signals, so each cell can target a wide variety of pathogens. c. The acquired immune system can mount an effective response within a few hours of infection.

146. What function does the innate immune system serve? a. The innate immune system takes time to ramp up in response to a specific antigen. b. Innate immune cells are important early in an infection, but after antibodies are produced they no longer contribute to eliminating the pathogens. *c. Innate immune cells recognize general “non-self” signals, so they can target pathogens or abnormal cells very early and quickly. d. All of the above.

147. What does “immunological memory” mean? a. The cells of the immune system store antigens from previous infections. *b. Acquired immune cells such as B and T cells are primed during the first infection. During the second infection, these cells can respond much more quickly. c. Once antibodies are generated, they never ever break down.

148. The function of B cells is to: *a. Produce antibodies, which bind to antigens. b. Activate cytotoxic T cells, which kill abnormal or infected cells. c. Attack antigen-bearing bodies marked with antibodies. d. Help T cells by providing growth signals.

149. Why is it so difficult to design a vaccine against HIV? a. HIV mutates very rapidly, so the antigens constantly change. b. HIV infects and kills cells that normally help fight off viral infections.

c. HIV integrates its genome into the host genome, so the viral DNA can hide from the immune system inside host cells. *d. All of the above.

150. The prion protein is transcribed from the ________ gene. a. PRIA *b. PRNP c. PPSC d. PRIO

151. Which of the following best describes the cause of prion diseases? a. The body is infected with the prion virus, which attacks the brain and lymph nodes of the animal. b. The body is infected with a bacterium, Clostridium prionii, when ingesting contaminated food, which then moves up the nervous system to the brain. c. The immune system attacks the body’s own tissues, reacting with the prion protein to cause inflammation in the brain. *d. The normal version of the prion protein in the body misfolds into a harmful conformation.

152. Prion diseases are often referred to as spongiform encephalopathies.  What does the term spongiform refer to? a. The organs of the animal’s body absorb excess water, like a sponge, and swell slightly. *b. The brain of the animal develops holes in it, so that it looks like Swiss cheese under the microscope. c. The heart of the animal develops holes in it, so that it looks like Swiss cheese under the microscope. d. The skin of the animal becomes soft and spongy to the touch.  153. Which of the following diseases is found in deer and elk and has spread from Colorado and the Western United States to other parts of the U.S. and Canada? a. TME (Transmissible mink encephalopathy) b. BSE (Bovine spongiform encephalopathy) *c. CWD (Chronic Wasting Disease) d. CJD (Creutzfeldt-Jakob Disease)

154. Which of the following prion diseases is found in a human, as opposed to a non-human mammalian host? *a. CJD (Creutzfeldt-Jakob Disease) b. CWD (Chronic Wasting Disease) c. TME (Transmissible Mink Encephalopathy) d. Scrapie

155. In class, we discussed Koch’s postulates as a methodology for scientists to confirm the cause of prion diseases (in other words, how can we confirm that prions cause the disease of scrapie?) Which of the following statements is NOT part of this process? a. We can detect (misfolded) prions in all cases of diseased sheep (sheep that are sick with scrapie). b. If we infect sheep with prions from another infected sheep, the sheep will become sick. *c. If we infect humans with prions from an infected sheep, the humans will become sick. d. We can identify the presence of prions in the new (experimentally infected) host.  156. Which of the following statements is incorrect? a. Infectious prions can spread to other organisms by the environment or by experimental inoculation. b. The normal prion protein is not harmful in the brain and has some functions, like binding copper. c. Prion diseases cause severe neurological issues and are inevitably fatal. *d. All of the prion diseases we studied in class are commonly found in humans.

157. What is the “protein hypothesis” in the context of prion diseases? a. Ingestion of a diet high in protein content has been recently proven to provide a therapy for those infected with prion diseases. *b. Prion diseases involve a misfolded version of protein in your body. c. The bacterium responsible for prion disease is highly fatal because of a toxic protein produced and secreted through the cell wall and cell membrane. d. Prion diseases are associated with the cleavage of an important protein in the gut of the

animal into three toxic pieces, leading to illness, neurological changes, and eventually death. 

158. Which of the following does NOT correctly describe a common feature of prion diseases, including the diseases we researched for class? a. They are associated with cognitive, behavioral, and other neurological signs and symptoms. b. They are associated with the same genetic locus in each case. c. They are associated with changes in the central nervous system.

*d. They are found in humans, mammals, and cold-blooded species such as fish and amphibians.  159. Scientists at the National Animal Disease Center…(complete the sentence) a. Work in teams composed of people with different specialties. b. Are part of the largest federally funded veterinary research facility. c. Must be very careful and safety conscious as they work with potentially deadly pathogens. *d. All of the above