1. Which of the following mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates? a. b. c. d. e. changing the force of heart contraction constricting and relaxing sphincters in the walls of arterioles adjusting the volume of blood contained in the veins all of the above none of the above

2. If you experimentally increase the concentration of K+ inside a cell while maintaining other ion concentrations as they were, what would happen to the cell's membrane potential? a. b. c. d. e. The membrane potential would become more negative. The membrane potential would become less negative. The membrane potential would remain the same. all of the above none of the above

3. Motor neurons release the neurotransmitter acetylcholine (Ach). What would you expect to happen if the acetylcholine is released in high concentrations and is not properly degraded after it binds the receptor on the postsynaptic membrane? a. b. c. d. e. paralysis of muscle tissue gradual loss of resting potential convulsions due to constant muscle stimulation decrease in the frequency of action potentials no effect

4. Compared to human eyes, the eyes of cephalopods (squid and octopus) ________. a. b. c. d. are extremely similar, with no significant differences are not camera eyes and do not have a single lens are inferior because they have few photoreceptors have an adaptive advantage because they do not have a blind spot e. none of the above

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Please use Figure 1 to answer the following 3 questions.

Figure 1 5. Which letter in Figure 1 corresponds to a large efflux of K+ ions from the cell? a. b. c. d. e. A B C D E

6. Which letter on Figure 1 corresponds to a hyperpolarization? a. b. c. d. e. A B C D E

7. Which letter on Figure 1 corresponds to the threshold potential? a. b. c. d. e. A B C D E

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8. In what way does hemoglobin act as a buffer against changes in blood pH? a. Subsequent binding of oxygen is drastically reduced after the first one is bound. b. Hemoglobin binds some of the excess protons released by carbonic acid. c. Hemoglobin produces protons or hydroxide ions as needed to alter the blood pH. d. Hemoglobin removes excess protons from the red blood cells so that they can be excreted through the kidneys. e. All of the above answers apply. 9. Birds are able to extract oxygen from the air efficiently enough to support long flights because: a. they exchange gases during both inhalation and exhalation b. the parabronchi of the lungs are a countercurrent exchange system, which allows for maximal gas exchange c. they have tidal airflow through their lungs d. they efficiently move one bolus of air through their respiratory system with one inhalation-exhalation cycle e. none of the above 10. Pressing on your eyelids with your fingers allows you to “see” light, although you are detecting a change in pressure instead of the presence of light photons. Your brain interprets the signal as “light” due to which of the following physiological principles? a. b. c. d. e. labeled line principle sensation principle signal override principle interpretation principle all of the above

11. Fick’s Law of Diffusion states that the rate of diffusion increases with: a. b. c. d. e. an increase in distance and area a decrease in distance and area an increase in distance, and a decrease in area a decrease in distance, and an increase in area none of the above

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12. Which of the following statements about action potentials is false? a. All action potentials for a given neuron are identical in magnitude. b. All action potentials for a given neuron are identical in duration. c. Action potentials are propagated down the length of the axon. d. Movement of ions during the action potential occurs mostly through the sodium pump. e. The frequency of action potentials, not their size, is the meaningful signal. 13. Memory studies with Aplysia have reinforced the idea that learning and memory, including long-term memory, occur as a result of: a. b. c. d. e. molecular changes in synapses structural changes in synapses changes in gene expression all of the above none of the above

14. Which of the following lists represents the pathway of light through the vertebrate eye? a. b. c. d. e. cornea → iris → pupil → retina → lens cornea → iris → pupil → lens → retina cornea → iris → lens → retina → pupil cornea → lens → pupil → iris → retina cornea → pupil → lens → iris → retina

15. The last step in the ability to sense a change in the environment is ___________________, or the processing of the signal with other incoming signals. a. b. c. d. e. amplification transduction transmission integration perception

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16. In vertebrates, the molecular basis of vision is a shape change in retinal that _____________ an ion channel and causes ______________ in the amount of neurotransmitter being released to the sensory neuron. a. b. c. d. e. opens; an increase opens; a decrease closes; an increase closes; a decrease none of the above

17. Action potentials are transmitted along myelinated nerve fibers by: a. b. c. d. e. diffusion active transport saltatory conduction graded potentials neurotransmitters

18. In a developing fetus, blood is shunted between the right and left atria via the __________________. a. b. c. d. e. ductus arteriosus foramen ovale ductus venosus pulmonary circulation circuit hepatic portal vein

19. Interstitial fluids lost at the beginning of a capillary bed are, for the most part, regained at the end of a capillary bed because: a. osmotic force exceeds hydrostatic force, resulting in fluid recovery b. hydrostatic force exceeds osmotic force, resulting in fluid recovery c. both osmotic force and hydrostatic force favor fluid recovery d. the osmolarity of capillary blood is low, favoring fluid recovery e. none of the above

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20. What is the function of sensory receptor cells? a. b. c. d. e. to receive a signal from the environment to transduce a signal from the environment to integrate a signal from the environment all of the above A and B only

21. Which of the following is not a true description of the transduction of a stimulus by sensory receptors into signals in the form of action potentials? a. Pressure from sound waves bends cilia in specialized hearing cells, causing ion channels in the plasma membrane to open or close and resulting in a change in ion flow that depolarizes or hyperpolarizes the membrane. b. Light can cause some molecules to change conformation, which then triggers a cascade of events leading to a change in the cell's membrane. c. Molecules in the air travel up the nose to mucous membranes, where they bend cilia in hair cells, open ion channels, and cause depolarization of the cell membrane. d. Na+ and H+ can flow through sodium and proton channels respectively to directly depolarize the cell membranes of some taste cells, causing the salty or sour taste sensations. e. Many types of molecules can bind to a variety of receptors in taste cells, leading to depolarization of the cell membrane and causing the taste sensation of bitterness. 22. The autonomic nervous system does not control ________. a. b. c. d. e. airway diameter contraction of skeletal muscle heart rate pupil dilation and constriction stomach activity

23. Human lungs are elastic because: a. b. c. d. e. they are composed of elastin fibers of surface tension of positive pressure ventilation when the diaphragm contracts, the lung volume decreases surfactants within the alveoli facilitate H-bonding 6

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24. An initial depolarization of a neuron leads to the opening of more Na+ channels, which depolarizes the membrane further. This is an example of ________________________. a. b. c. d. e. positive feedback negative feedback homeostasis an EPSP feedback inhibition

25. The two hemispheres of the human brain are connected by a thick band of axons called the ________________________. a. b. c. d. e. brain stem cortex cerebellum corpus callosum medulla

26. Pit vipers can detect and strike in complete darkness because of their ability to detect ________. a. b. c. d. e. infrared wavelengths ultraviolet wavelengths rapid movements odors at extremely low concentration none of the above

27. IPSPs ______________ the postsynaptic plasma membrane, while EPSPs _________________ the postsynaptic plasma membrane. a. b. c. d. e. locally depolarize, locally hyperpolarize locally hyperpolarize, locally depolarize locally depolarize, have no effect on have no effect on, locally hyperpolarize locally hyperpolarize, have no effect on

28. What causes rigor mortis? a. b. c. d. e. exhaustion of Ca2+ from the sarcoplasmic reticulum lack of ATP in dead tissue lack of acetylcholine (ACh) in dead tissue cessation of action potentials after death all of the above 7

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29. Hard contact lens wearers are advised not wear their contacts for an extended period of time because the cornea of a human’s eye: a. b. c. d. e. contains no blood supply needs to diffuse oxygen into it from the environment needs to diffuse CO2 out into the environment B and C only all of the above

30. Premature infants may not produce surfactants in the alveoli of their lungs. What implications does this have for their health and survival? a. The partial pressure of oxygen drops significantly in the absence of these surfactants, and the child may suffer brain damage from oxygen deprivation. b. The surface tension of fluids in the lungs may be too high for the lungs to expand fully during inhalation. c. Surfactants are necessary to trap pollutants and other material that enters the lungs during inhalation; thus, lung disease is more likely. d. Surfactants raise the surface tension of alveolar fluids so that deoxygenated air does not get trapped in the lungs during exhalation. e. none of the above 31. A mutation results in a form of hemoglobin that has binding sites for four molecules of oxygen but does not exhibit cooperative binding. Which of the following would result? a. Each hemoglobin molecule would bind only one molecule of oxygen. b. Oxygen would be delivered to the tissues more readily than in a normal individual. c. The oxygen-hemoglobin dissociation curve would be unaffected. d. Both A and C would occur. e. None of the above would result.

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32. The Bohr shift makes hemoglobin _________ likely to release oxygen to tissues with _________ pH. a. b. c. d. e. more, low more, neutral less, low less, high more, neutral

33. The resting membrane potential of a typical mammalian cell is around -70 mV. This charge is due to more _________ charge outside the cell relative to the inside, and is maintained by ________________. a. b. c. d. e. negative, sodium-potassium pumps negative, voltage-gated channels positive, sodium-potassium pumps positive, voltage-gated channels positive, chloride channels

34. Which type of receptor would you expect to be most abundant in the antennae of a moth? a. b. c. d. e. thermoreceptors mechanoreceptors chemoreceptors electroreceptors nociceptors

35. Many different molecules are perceived as ____________ tasting. Researchers hypothesize this taste evolved in response to selection for avoiding toxic molecules. a. b. c. d. e. sweet salt acid bitter meaty

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36. What would probably happen if a long neuron had one continuous myelin sheath down the length of the axon with no nodes of Ranvier? a. The action potential would be propagated nearly instantaneously to the synapse. b. There could be no action potential generated at the axon hillock. c. The signal would fade because it is not renewed by the opening of more sodium channels. d. All of the above could happen. e. None of the above could happen. 37. Bottlenose dolphins (Tursiops truncatus) transmit most sound signals to their ears via _______________________. a. b. c. d. e. their external auditory canal their lower jaw their pectoral flippers their melon their external ear (pinnae)

38. A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing. Why? a. The percentage of oxygen in the air at high elevations is lower than at sea level. b. The percentage of oxygen in the air at high elevations is higher than at sea level. c. The partial pressure of oxygen in the air at high elevations is lower than at sea level. d. The partial pressure of oxygen in the air at high elevations is higher than at sea level. e. Both A and C

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39. The squid giant axon is approximately 500 μm in diameter (compared to 2 μm for a typical human axon). Due to the size of the axon, ________. a. it can transmit action potentials much faster than small axons can b. it can transmit action potentials at a higher frequency (i.e., fire faster) than small axons can c. it can generate larger amplitude action potentials than small axons can d. it can generate longer duration action potentials than small axons can e. Both A and C 40. Fetal hemoglobin (Hb) has a ________________ affinity for oxygen compared to maternal hemoglobin; thus, the oxygen-hemoglobin equilibrium curve for fetal Hb is ____________ with respect to the curve for maternal Hb. a. b. c. d. e. lower, shifted to the left higher, shifted to the left lower, shifted to the right higher, shifted to the right similar, not shifted at all

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