BIOLOGY 1520 MOD2
A defining feature a reflex arc is that: A) The brain is not involved in responding to the stimulus B) The entire arc is mediated exclusively by the PNS C) Efferent neurons are capable of depolarizing without signals from afferent neurons D) Sensory neurons relay the signal from the stimulus directly to the muscles fibers E) The sympathetic division overrides any signals from the parasympathetic division
A
Both epinephrine and cortisol are secreted in response to stress. Which of the following statements is also true for both of these hormones? A. They act to increase blood glucose availability. B. Their receptors are on the surfaces of target cells. C. They are secreted by the adrenal cortex. D. Their secretion is stimulated by adrenocorticotropic hormone (ACTH) (corticotrophin). E. They are secreted into the blood within seconds of the onset of stress.
A
Fast-twitch fibers differ from slow-twitch fibers in that A. they are more common in the leg muscles of champion sprinters than marathon runners. B. they have more mitochondria. C. they fatigue less rapidly. D. their abundance is more a product of training than of genetics. E. they are more common in postural muscles than in finger muscles.
A
In the complete absence of light, a rod will A. become strongly depolarized and increase its release of neurotransmitters B. become strongly hyperpolarized and decrease its release of neurotransmitters C. become strongly hyperpolarized and increase its release of neurotransmitters D. become strongly depolarized and decrease its release of neurotransmitters E. None of these
A
In the human brain, the interneurons in the medulla are myelinated while the outer cortex is demyelinated. The outer layer of the spinal cord is myelinated, while the interior neurons are lack myelin. Which of the following statements correctly explains this difference? A. Information is integrated in the cortex of the brain, while information is integrated in the internal layers of the spinal column. B. There is no relationship between the functions of these structures and their myelination. C. Information is integrated in the medulla of the brain, while information is integrated in the external layers of the spinal column. D. During the reflex arc, sensory stimuli is transmitted from the inner layers of the spinal column to the cortex of the brain. E. None of the above are accurate.
A
Pain is best described as A) a sensation perceived in the CNS as a result of tissue damage somewhere in the body B) A sensation perceived in the CNS in response to stimulation of mechanoreceptors in the PNS C) a stimulus detected by nociceptors in the PNS D) A stimulus detected by mechanoreceptors or thermoreceptors in the PNS E) All of the above are accurate descriptions of pain
A
The "white meat" (light-colored muscle) of a chicken: A) is primarily composed of fast-twitch fibers B) has greater amounts of myoglobin C) utilizes oxidative rather than glycolytic ATP synthesis D) has greater numbers of sodium-potassium pumps in the plasma membrane E) is higher endurance (less likely to suffer fatigue) compared to "dark meat" muscles
A
Touch receptors in the skin detect pressure. Ion channels in the touch receptor cell membranes open when: A) The membrane is mechanically distorted B) Neurotransmitters are released from the synapsed efferent neuron C) Light is absorbed by a molecule in the membrane D) The cell membrane reaches the threshold voltage E) A chemical binds the ion channel
A
What would be the effect of treating immature apples with gibberellins as they were growing on the tree? A) The fruit would grow larger than normal B) The tree branches would bend toward the source of the gibberellins C) The fruit would ripen too early and be too small D) The fruit would be replaced by flowers E) The tree branches would germinate
A
Which of the following does not accurately describe either olfaction or gustation? A. Each olfactory receptor cell contains receptors for multiple odorants. B. Taste receptor cells become depolarized and release neurotransmitters upon stimulation by tastants. C. Each taste bud contains receptor cells for all types of tastants. D. The ability to perceive flavor is dependent upon both taste and olfactory receptor cells. E. Olfactory receptor cells are neurons; taste receptor cells are receptor cells synapsed with neurons.
A
Which of the following is FALSE regarding hormone function? A) Hormones only affect specific cells in the body because those are the only cells exposed to the hormone B) The same hormone may have different effects on different cell types due to activation of different signaling pathways within the cells C) A very small quantity of a hormone can produce a large effect due to signal amplification D) The same hormone may have different effects on different cell types due to different types of hormone receptors in the different cells E) All of the above are true
A
Which of the following statements about plant hormones is false? A. Cytokinins inhibit cell division. B. Abscisic acid is not involved in abscission (leaf detachment from a plant). C. Gibberellins stimulate cell enlargement. D. Ethylene contributes to the ripening of fruit. E. Plant hormones are small molecules, easing diffusion through the plant body.
A
A neuron receives electrical signal from other neurons along its: A) Gated ion channels B) Dendrites C) Axon D) Neurotransmitters E) Axon hillock
B
Analysis of a blood sample taken form a patient after a long period of fasting would be expected to reveal high levels of: A) Insulin B) Glucagon C) Epinephrine D) Leptin E) Progesterone
B
Contractile proteins (which can act to shorten cells or perform work) include: A. actin B. myosin C. microtubules D. A and B E. A, B, and C
B
Exposure to _____ light will _____ plant processes, such as germination but exposure to ______ light will ______ that process. A. far red, activate, red, inhibit B. far red, inhibit, red, activate C. blue, inhibit, far red, activate D. blue, activate, red, inhibit E. light wavelength is not important, rather photoperiod (length of exposure) determines plant responses to light
B
If you were blindfolded while sitting in a rolling office chair, how could you determine whether you were being pushed forwards or backwards? A. The hairs on the surface of the skin bend in order to relay the primary sensation of motion. B. Calcium carbonate crystals (otoliths) shift in response to motion, which is recognized by hair cells in the ear. C. The motion causes regions of the basilar membrane to vibrate at differing imperceptible frequencies. D. The fluid surrounding the cerebral cortex redistributes in response to motion, which is recognized by the parietal lobe. None of the above are accurate
B
In bright light, a rod will: A) Become strongly depolarized and increase its release of neurotransmitters B) become strongly hyperpolarized and decrease its release of neurotransmitters C) Become strongly hyperpolarized and increase its release of neurotransmitters D) become strongly depolarized and decrease its release of neurotransmitters E) None of these
B
In humans, the region of the retina where the central part of the visual field falls is the A. central ganglion cell. B. fovea. C. optic nerve. D. cornea. E. pupil.
B
Muscle contraction is controlled by A. Movement of actin motor proteins along myosin filaments B. Movement of myosin motor proteins along actin filaments C. Shortening of actin filaments along myosin filaments D. Shortening of myosin filaments along actin filaments E. A and B
B
Sensory receptors (e.g. hearing, taste, smell, etc) provide information on the stimulus intensity to the CNS by: A. the differing variety of sensory receptors responding to a common stimulus B. the frequency of action potentials C. a sensory receptor-reflex arc D. the spinal cord E. specialized region(s) of the cerebrum
B
The binding of an inhibitory neurotransmitter to the postsynaptic receptors results in which of the following? A. Depolarization of the membrane B. Hyperpolarization of the membrane C. Generation of an action potential D. Increased permeability of the membrane to sodium ions E. Increased permeability of the membrane to calcium ions
B
The transduction of sound waves into action potentials occurs due to: A) vibrations in the semicircular canals that stimulate the basilar membrane B) Bending of hair cells due to movement of the basilar membrane C) Amplification of sound waves by ossicles of the middle ear D) movement of ear stones within the cupulas of the semicircular canals E) Stimulation of hair cells in cupulas along the tectorial membrane
B
What is the function of Ca2+ in muscle cells? A. It regulates how hard the muscle contracts B. It removes troponin to remove the tropomyosin-complex from the binding sites C. It creates involuntary muscle movement by causing sarcomeric change D. It increases the rate of ADP flow to the muscle to cause the myosin head to bind E. B and D
B
What is the role of Ca2+ in the control of muscle contraction? A. Cause depolarization of the T-tubule system. B. Change the conformation of troponin, thus exposing myosin binding sites. C. Change the conformation of myosin heads, thus causing microfilaments to slide past each other. D. Bind to tropomyosin and break actin-myosin cross-bridges. E. Block the ATP-binding site on myosin heads, enabling muscles to relax.
B
Which membrane is most directly responsible for the ability to determine pitch? A. Round window B. Basilar membrane C. Oval window D. Tympanic membrane E. Tectorial membrane
B
Which of the following is NOT a correct pairing between concept and example of that concept? A) Crosstalk: In vertebrates, combinations of estradiol and progesterone prevent follicle maturation; high levels of estradiol alone stimulate follicle maturation B) Negative feedback: In plants, cytokinins promote cell division when auxin is present, cell division is inhibited when auxin is absent C) Positive feedback: In placental mammals, oxytocin stimulates uterine contractions during birth; increased uterine contractions lead to release of more oxytocin D) All of the above are correct pairings E) None of the above are correct pairings
B
Which of the following is NOT a mechanism for relaying the sensory signal intensity to the CNS? A) How frequently an action potential propagates along the sensory neurons B) The size of the action potential propagated along the sensory neurons C) The number of sensory neurons activated D) Which specific sensory neurons are activated E) All of the above are mechanisms for relaying degree of a particular stimulus to the CNS
B
Which of the following is NOT true of quorum sensing? A) Quorum sensing can induce behavioral changes in single cells B) Quorum sensing occurs when cells produce a signaling factor because they are in high abundance C) A molecule which prevented quorum sensing could be useful as an antibiotic D) Formation of biofilms occurs as a result of quorum sensing E) All of the above are true of quorum sensing
B
Which of the following is responsible for rigor mortis (muscle stiffness after death)? A. The cessation of action potentials after death B. The lack of ATP in dead tissue C. The lack of acetylcholine (ACh) in dead tissue D. The exhaustion of Ca2+ from the sarcoplasmic reticulum E. None of the above explain rigor mortis.
B
Which of the following is the FALSE regarding the control of contraction of a skeletal muscle fiber? A) T tubules transmit the depolarization of the muscle fiber membrane into the sarcoplasmic reticulum B) The sarcoplasmic reticulum contains calcium, which blocks contraction upon release C) Troponin and tropomyosin regulate access of the myosin heads to the actin filament D) ATP is required to release the myosin heads from the actin filament E) All of the above are true
B
Which of the following neuron structures are matched with the correct function? A. Dendrites; cells that cover the axon in myelin in the central nervous system B. Axon; transmits signals from the cell body to the synapse via electrical signaling. C. Synapse; a close physical connection where electrical signals are conducted between two neurons. D. Oligodendrites; cellular projections that receive signals from neighboring neurons. E. All of the above are correctly matched
B
Which of the following statements about sensory cells is false? A. Mechanoreceptors detect stimuli that distort membranes. B. Chemoreceptors are involved in smell, taste, and hearing. C. Photoreceptor molecules exhibit a conformational change when stimulated by light. D. Nociceptors respond to harmful stimuli. E. All of the above are true.
B
Which of the following would likely be true of an individual who produces excessive amounts of leptin peptide? A) They would be overweight B) They would be underweight C) They would have high levels of insulin in the bloodstream D) A and C E) B and C
B
Which of the followings statements concerning phytochromes is correct? A. It is the only photoreceptor pigment in plants. B. It exists in two forms interconvertible by light. C. It is a pigment that is colored red or far-red. D. It is a green-light receptor. E. It is the photoreceptor for phototropism in coleoptiles.
B
Cytokinins promote cellular division in plants, but only when in the presence of auxin. This system is an example of which type of regulation? A. Positive feedback B. Negative feedback C. Hormonal crosstalk D. A and C E. None of the above
C
Insects go through several larval molts as they grow larger, and one final molt for metamorphosis into a sexually mature adult. A surge of ecdysone causes molting; ecdysone in combination with juvenile hormone causes molting into the next larval stage; ecdysone in the absence of juvenile hormone causes molting with metamorphosis into an adult. What would happen to an insect with nonfunctional ecdysone receptors? A) The insect would molt into an adult upon the next ecdysone surge B) The insect would always molt into another larval stage and would never molt into an adult C) The insect would never molt at all D) The insect would immediately molt into an adult upon hatching from its egg E) The insect would molt into an adult at the normal time
C
Learning and memory can be mediated by: A) Change in the speed of action potentials in response to a repeated stimulus B) Change in the strength of action potentials in response to a repeated stimulus C) Growth or destruction of synapses between neurons in response to a repeated stimulus D) All of the above are true E) None of the above
C
Muscle contraction is graded, while the neuronal signals that initiate it are "all or nothing." Which of the following is a mechanism responsible for graded muscle contraction? A. Variable numbers of T-tubules depolarized B. Variable sizes of action potentials in efferent neurons C. Variable frequencies of action potentials in efferent neurons D. Variable numbers of myosin thick filaments activated by ATP
C
The list below includes various stages in the signal transmission at a chemical synapse, in no particular order. 1. Synaptic vesicles release neurotransmitters into the synaptic cleft 2. Neurotransmitters bind with receptors on the postsynaptic membrane 3. Calcium ions rush into the neuron's cytoplasm 4. An action potential depolarizes the membrane of the presynaptic axon terminal 5. Ion channels open on the postsynaptic membrane Which sequence of events is correct? A) 2, 3, 5, 4, 1 B) 1, 2, 3, 4, 5 C) 4, 3, 1, 2, 5 D) 3, 2, 5, 1, 4 E) 5, 1, 2, 4, 3
C
The perceived volume of a sound depends on: A) Whether the sound moves the incus, malleus, or stapes B) Which region of the basilar membrane vibrates C) The frequency of action potentials generated by hair cells in the cochlea D) The size of the action potential generated by hair cell sin the cochlea E) Which part of the oval window produces waves int eh cochlear fluid
C
The resting potential of a neuron is due mostly to A. open Na+ channels. B. synaptic summation. C. open K+ channels. D. open Cl- channels. E. None of the above
C
The rising phase of an action potential is due to the A. closing of K+ channels. B. opening of chemically gated Na+ channels. C. opening of voltage-gated Na+ channels. D. closing of voltage-gated Ca2+. E. spread of positive current along the plasma membrane
C
Which of the following is TRUE regarding the different structural classes of hormones? A) The more structurally complex hormones, such as polypeptide hormones, induce stronger responses in cells than hormones with simpler structures B) Smaller hormones, such as amino acid-derived hormones and steroid hormones, are able to circulate through the body more quickly and thus induce responses faster than larger hormones C) Steroid hormones pass into the cell to bind to their receptors; amino acid-derived and polypeptide hormones must bind to receptors at the cell surface D) Different structures allow two different hormones to have different effects on the same hormone receptor E) All of the above are true
C
Which of the following is the correct sequence that describes the contraction of a skeletal muscle fiber? 1) Depolarization is spread via T tubules to the sarcoplasmic reticulum. 2) Calcium is released and binds to the troponin complex. 3) The phosphate ion is released from myosin. 4) ADP is released from myosin. 5) Tropomyosin shifts and unblocks the cross-bridge binding sites. A. 5 → 3 → 1 → 2 → 4 B. 1 → 5 → 2 → 4 → 3 C. 1 → 2 → 5 → 3 → 4 D. 2 → 5 → 1 → 4 → 3 E. 5 → 1 → 2 → 3 → 4
C
Which of the following statements is correct? A. The resting potential across a membrane is about +65 mV. B. Sodium may freely pass through the membrane via "leaky channels". C. The sodium/potassium pump obtains energy from the hydrolysis of phosphate groups. D. A and B E. A and C
C
Which process is not directly affected by auxin? A. Apical dominance B. Leaf abscission C. Seed germination D. Root initiation E. Cell elongation
C
Which statement about cone cells in a human eye is not true? A. They are responsible for our sharpest vision. B. They are responsible for color vision. C. They are more sensitive to light than rods are. D. They are fewer in number than rods. E. They exist in high numbers at the fovea.
C
Which statement accurately describes an action potential? A. Its magnitude increases along the axon. B. Its magnitude decreases along the axon. C. All action potentials in a single neuron are of the same magnitude. D. During an action potential, the membrane potential of the neuron remains constant. E. An action potential permanently shifts a neuron's membrane potential away from its resting value.
C
A neuron that has just fired an action potential cannot be immediately restimulated to fire a second action potential. The short interval of time during which restimulation is not possible is called A. hyperpolarization. B. repolarization. C. the resting potential. D. the refractory period. E. depolarization.
D
A scientist is observing various axons. She notices that axons taken from different species produce action potentials with varying speeds. Which of the following may explain this phenomenon? A. The diameters of the axons are different. B. The axons display different levels of myelination. C. The speeds of action potentials may vary within the same axon. D. Both A and B explain this occurrence. E. None of the above are true; all axons relay messages at the same speed.
D
All types of sensory signal transduction are based on the production of A. action potentials in the sensory receptor cells. B. increased frequency of action potentials in the sensory receptor cells when more deeply stimulated. C. graded depolarizations in the sensory receptor cells. D. graded changes in membrane potential in the sensory receptor cells. E. A and B
D
Reflexes such as the knee-jerk reflex result in a very rapid involuntary response to a stimulus without altering activity in A. motor neurons. B. sensory neurons. C. the spinal cord. D. the brain. E. All of the above are altered.
D
Signal transduction refers to processes that occur in both chemical and electrical signaling. In both of these contexts, signal transduction refers to: A) Recognition of the signal by the cell B) Interference from another signal which changes the cell's response C) Amplification of the signal to provoke a greater response D) Changing the signal from one form to another E) None of the above are accurate descriptions of signal transduction
D
The color in color vision results from the A. ability of each cone cell to absorb all wavelengths of light equally. B. lens of the eye acting like a prism and separating the different wavelengths of light. C. differential absorption of wavelengths of light by different kinds of rod cells. D. three different isomers of opsin in cone cells. E. absorption of different wavelengths of light by amacrine and horizontal cells.
D
The stress response can be more easily induced in an individual suffering from post-traumatic stress disorder compared to an individual not affected by this disorder. This phenomenon is due to the process of: A) Integration B) Depolarization C) Habituation D) Sensitization E) Myelination
D
What is the correct order for the following event in the interaction of a cell with a signal? (1) alteration of cell function; (2) signal binds to a receptor; (3) signal released from source; (4) signal transduction. A. 1→2→3→4 B. 2→3→1→4 C. 3→2→1→4 D. 3→2→4→1 E. 3→4→2→1
D
What process could be responsible for the shift between number 1 (on action potential graph) and the horizontal dashed line? A) Multiple EPSPs occurring in different locations on the cell body at the same time B) Multiple EPSPs occurring in the same location on the cell body in rapid sequence (one right after the other) C) Graded depolarization in the cell body sufficient to overcome the axon hillock D) All of the above E) None of the above
D
Which of the following conditions would stimulate a molting larval insect to transform into a larger larval stage? A. decreased level of ecdysone B. lack of juvenile hormone C. lack of the melatonin hormone D. increased level of juvenile hormone E. lack of ecdysone
D
Which of the following is FALSE regarding musculoskeletal systems? A) Cardiac muscle contraction is controlled by the autonomic nervous system B) Rigor mortis (muscle stiffness after death) occurs due to lack of ATP in the dead tissue C) Muscles are paired in all types of skeletal systems (hydrostatic, exo, and endo) because muscles can only contract; there is no mechanism for muscle extension D) Muscle contraction is mediated by the shortening the sarcomere, which results from shortening of myosin and/or actin filaments E) All of the above are true
D
Which of the following is NOT required for movement of cilia, flagella, and muscles? A) Motor proteins B) ATP C) Motor protein tracks D) Action potentials E) All of the above are required for movement of cilia, flagella, and muscles
D
Which of the following is TRUE of olfaction and gustation? A) A single olfactory receptor cell is capable of detecting multiple different odorants B) A single taste bud is specific to one type of tastant C) The sense of taste relies entirely on taste buds and adequate saliva levels D) The sense of smell requires that odorants be dissolved in nasal mucus E) All of the above are true
D
Which of the following is TRUE of plant responses to pathogens and herbivores? A) Controlled, localized cell death is beneficial to the plant during infection B) A localized infection or herbivory attack will promote a system (body-wide) response C) Herbivory can result in release of volatile organic compounds that attract other animals that attack the herbivores D) All of the above are true E) None of the above are true
D
Which of the following is true of gibberellins? A. They are responsible for phototropism and gravitropism. B. They are gases at room temperature. C. They are produced by fungi exclusively. D. They cause flowering in plants. E. They inhibit the synthesis of digestive enzymes by barely seeds.
D
Which of the following statements correctly describe(s) T tubules and their role in conducting action potentials in muscle cells? A. Without T tubules, the muscle cell would not be able to contract. B. tubules have receptor proteins that bind neurotransmitters released from the synaptic terminal of the motor neuron. C. tubules carry action potentials throughout the muscle cell D. A and C E. B and C
D
Which statement about sensory systems is not true? A. Sensory transduction involves the conversion (direct or indirect) of a physical or chemical stimulus into changes in membrane potential. B. In general, a stimulus causes a change in the flow of ions across the plasma membrane of a sensory receptor cell. C. Habituation is the decreased response to a stimulus that has been repeated without an important effect. D. The more intense a stimulus, the greater the magnitude of each action potential fired by a sensory neuron. E. Sensory adaptation plays a role in the ability of organisms to discriminate between important and unimportant information.
D
Which statement is not true? A. The transmembrane potential of a rod cell becomes more negative when the rod cell is exposed to light. B. A photoreceptor releases the most neurotransmitter when in total darkness. C. Whereas in vision the intensity of a stimulus is encoded by the degree of hyperpolarization of photoreceptors, in hearing the intensity of a stimulus is encoded by changes in firing rates of sensory neurons. D. The interaction among hammer (malleus), anvil (incus), and stirrup (stapes) conducts sound waves across the fluid-filled middle ear. E. Stiffening of the ossicles in the middle ear can lead to deafness.
D
Why do some signals ("first messengers") trigger "second messengers" to activate target cells? A. The first messenger requires activation by ATP. B. The first messenger is not water soluble. C. The first messenger binds to many types of cells. D. The first messenger cannot cross the plasma membrane. E. There are no receptors for the first messenger.
D
A drug which blocks voltage-gated potassium channels in axons would most likely impact which part of the graph above (action potential graph)? A) 1 B) 2 C) 3 D) 4 E) 3 and 4
E
A seed exposed to both red light and abscisic acid simultaneously will most likely: A) Germinate because both of these promote germination B) Remain dormant because both of these prevent germination C) Remain dormant because one of these prevents germination while the other does not play a role in germination D) Germinate because one of these promotes germination while the other does not play a role in germination E) Cannot be predicted because these play opposing roles in germination
E
An individual who suffered a traumatic brain injury and can no longer maintain homeostasis probably has damage to the: A) cerebral cortex B) brain stem C) cerebellum D) temporal lobe E) diencephalon
E
Auxin regulates many different processes in plants. In the case of gravitropism and phototropism: A) Asymmetric distribution of auxin in the root or shoot promotes bending B) Auxin distribution shifts due to exposure to blue light in shoots, and due to movement of amyloplasts in roots C) Shoots bend away from the side with more auxin, and roots bend away form the side with less auxin D) A and B E) All of the above are true
E
During the middle of a winter's night, various plants were flashed with red light and then far-red light. Which of the following statements are correct? A. Long day plants will bloom B. Long day plants will not bloom C. Short day plants will bloom D. Short day plants will not bloom. E. B and C
E
For a neuron with an initial membrane potential at -70 mV, an increase in the movement of sodium ions into that neuron's cytoplasm would result in A. the replacement of potassium ions by the sodium ions. B. the neuron switching on its sodium potassium pump to restore the initial conditions C. the replacement of potassium ions with calcium ions D. hyper polarization of the neuron E. depolarization of the neuron
E
Glucocorticoids do which of the following? A. promote the release and breakdown of fatty acids B. increase blood glucose levels C. promote the immune response D. increase insulin production E. A and B
E
Muscle contraction is graded, while the neuronal signals that initiate it are "all or nothing." Which of the following is NOT a mechanism responsible for graded muscle contraction? A) Variable frequencies of "twitches" initiated by the effector neuron B) Variable numbers of motor units activated C) Variable numbers of muscle fibers activated D) Variable frequencies of action potentials form the effector neurons E) All of the above are mechanisms responsible for graded muscle contraction
E
Nociceptors are sensory receptors sensitive to: A. strong or light touch B. photons C. pain D. any degree of heat E. tissue damage
E
Surgical removal of which of the following structures would cause the most wide-reaching effects on the mammalian body? A) Adrenal glands B) Pancreas C) Thyroid gland D) Gonads (ovaries or testes) E) Pituitary
E
The eyes of the mantis shrimp contain 16 different types of cone cells. This observation suggests that the mantis shrimp: A) Has 16 different types of retinals B) Can differentiate between up to 16 different colors C) Can see in very low light levels D) All of the above E) None of the above
E
The steps below refer to various stages in an action potential: 1. The sodium-potassium pump redistributes ions, resetting the membrane potential. 2. Voltage-gated sodium channels open quickly after depolarization past the threshold potential. 3. A mechanical disturbance causes sodium ions to enter the intracellular space. 4. Voltage-gated potassium ion channels open, repolarizing the membrane. 5. The membrane potential drops below the resting potential. Which sequence of events is correct: A. 2→3→4→1→5 B. 1→2→5→3→4 C. 3→5→2→1→4 D. 2→4→1→5→3 E. 3→2→4→5→1
E
What is the role of the actin (thin) filament in muscle contraction? A. has motor protein heads that hydrolyze ATP B. filament that is pulled towards the center of the sarcomere C. filament that pulls the other filament towards the center of the sarcomere D. binding sites for motor protein head E. B and D
E
Which of the following is false regarding the peripheral nervous system (PNS)? A. The PNS includes the sympathetic and parasympathetic divisions. B. The PNS includes sensory and effector neurons. C. The PNS controls both voluntary and involuntary responses to stimuli. D. The PNS can relay information to both the brain and the spinal column for signal processing. E. All of the above are true.
E
Which of the following is true of the PNS? A) The sympathetic division controls the short-term stress response, and the parasympathetic division controls the long-term stress response B) The afferent division controls involuntary responses and the efferent division controls voluntary responses C) The spinal cord contains the interneurons of the PNS, while the brain contains the interneurons of the CNS D) All of the above are true E) None of the above are true
E
Which of the following statements concerning graded membrane potentials is correct? A. They can be more negative than resting potential. B. They can be less negative than resting potential. C. They integrate the many synaptic inputs to a cell. D. They are important means of summing sensory inputs. E. All of the above are correct.
E
Which statement about olfaction is false? A. Olfactory stimuli are recognized by the interaction between odorant molecules and receptor molecules. B. The more odorant molecules that bind to receptors, the more action potentials are generated. C. The greater the number of action potentials generated by an olfactory receptor, the greater the intensity of the perceived smell. D. The perception of different smells results from the activation of different combinations of olfactory receptors. E. Each of the statements above are true.
E