(BIO 1120) BIOLOGY 1120 EXAM 2 QUESTIONS AND CORRECT ANSWERS (EXPERT VERIFIED) JUST RELEASED| 2025/2026 | SURE TO PASS !!

(BIO 1120) BIOLOGY 1120 EXAM 2 QUESTIONS AND CORRECT ANSWERS (EXPERT VERIFIED) JUST RELEASED| 2025/2026 | SURE TO PASS !! 1. Which is specifically a part or a function of the central nervous system? A) dendrites B) motor output C) integration D) sensory receptors - ANSWER C) integration 2. Which statement is true? A) Ion channels allow ions to cross the cell membrane against their concentration gradients. B) All cells have an equilibrium potential, a difference in electrical charges across their plasma membrane. C) Concentration gradients of proteins across the plasma membrane represent potential energy. D) Ion channels are selectively permeable, permitting only certain ions to pass. - ANSWER D) Ion channels are selectively permeable, permitting only certain ions to pass. 3. Blocking potassium ion channels in a mammalian cell membrane would __________. A) increase the resting potential B) decrease the magnitude of the membrane potential C) increase potassium's equilibrium potential D) decrease sodium's equilibrium potential E) increase the magnitude of the membrane potential - ANSWER B) decrease the magnitude of the membrane potential 4. An increase in the magnitude of the membrane potential is called __________. A) hyperpolarization B) depolarization C) a refractory period D) hypopolarization - ANSWER A) hyperpolarization 5. A drug that causes potassium to leak out of a neuron, increasing the positive charge on the outside, would __________. A) make it easier to trigger action potentials in the neuron B) speed up nerve signals traveling the length of the cell C) inhibit transmission of nerve signals by the neuron D) cause the cell to release its neurotransmitter act as a stimulant - ANSWER C) inhibit transmission of nerve signals by the neuron 6. Schwann cells make up the __________. A) myelin sheath in the CNS B) axons C) nodes of Ranvier D) myelin sheath in the PNS E) neurons - ANSWER D) myelin sheath in the PNS 7. An action potential is __________. A) a sudden increase in speed by the sodium potassium pump B) a brief neutralization of the charges on sodium and potassium ions C) a traveling wave of depolarization in the neuron membrane D) a sudden reversal of the sodium-potassium pump - ANSWER C) a traveling wave of depolarization in the neuron membrane 8. The interplay of multiple excitatory and inhibitory inputs most affects what part of a neuron? A) axon hillock B) the nucleus C) dendrites D) the axon - ANSWER A) axon hillock 9. Which is a mechanism by which neurotransmitters can be rapidly cleared from the synaptic cleft? A) The neurotransmitters are actively transported back into the presynaptic cells to be repackaged into synaptic vesicles. B) The neurotransmitters are actively transported into glia to be metabolized as fuel. C) Neurotransmitters are removed by simple diffusion. D) Neurotransmitters are removed by enzymes that catalyze hydrolysis of the neurotransmitter. E) All of the choices are correct. - ANSWER E) All of the choices are correct. 10. Which correctly pairs a type of synapse and a key component of that synapse? A) electrical synapse ... neurotransmitters B) electrical synapse ... gap junctions C) chemical synapses ... gap junctions D) junctional synapses ... ligand-gated ion channels - ANSWER B) electrical synapse ... gap junctions 11. Acetylcholinesterase is the enzyme that degrades acetylcholine. What effect on nerve transmission would occur following the administration of a chemical that inhibited acetylcholinesterase? A) Continuous excitatory postsynaptic potentials would occur in the postsynaptic neuron. B) It would be identical to giving an anesthetic, but it would last permanently. C) Synaptic transmission would be prevented; muscle paralysis would occur. D) The presynaptic neuron would be inactivated. - ANSWER A) Continuous excitatory postsynaptic potentials would occur in the postsynaptic neuron. 12. The cerebral cortex plays a major role in A) circadean rhythms. B) temperature regulation. C) breath holding. D) heart activity. - ANSWER C) breath holding. 13. The middle ear converts A) air pressure waves to fluid pressure waves. B) air pressure waves to nerve impulses. C) fluid pressure waves to nerve impulses. D) pressure waves to hair cell movements. - ANSWER A) air pressure waves to fluid pressure waves. 14. If the following events are arranged in the order in which they occur for an animal hiding and holding still in response to seeing a predator, which is the fourth event in the series? A) signaling by an afferent PNS neuron B) signaling by an efferent PNS neuron C) information processing in the CNS D) activation of a sensory receptor - ANSWER B) signaling by an efferent PNS neuron 15. Which statement is correct? A) Dendrites branch off axons. B) The peripheral nervous system is most closely associated with interneurons. C) Axons receive signals from other neurons. D) A neuron only has a single axon. - ANSWER D) A neuron only has a single axon. 16. Which statement is correct? A) The vast majority of neurons in the brain are sensory neurons. B) Synaptic cells nourish neurons, insulate the axons of neurons, and/or regulate the extracellular fluid surrounding the neurons. C) Sensory neurons transmit signals to muscle cells. D) None of the choices is correct. - ANSWER D) None of the choices is correct.