Neurobiology: Practice Exam I with correct answers 100% 2026

Neurobiology: Practice Exam I with correct answers 100% 2026 nerve cells are ____ conductors of electricity - Correct Answer poor a myelinated neuron has ____ membrane resistance and ____ longitudinal resistance - Correct Answer high low Which is not a kind of potential exhibited by neurons? a. reaction b. action c. synaptic d. resting e. post synaptic - Correct Answer reaction electrical signals occurring in nerve cells are cause by ____the cell membrane - Correct Answer fluxes of ions across Which of the following is not required for neurons to communicate? - Correct Answer separation of larges amounts of electrical charge, with excess positive charge stored inside the cell The transmembrane potential is generated by - Correct Answer diffusion of ions down a concentration gradient T/F Action potentials are elicited by hyperpolarization. - Correct Answer FALSE 8. Which of the following statements about electrochemical equilibrium is FALSE? A. Electrochemical equilibrium involves the movement of a relatively small number of ions. B. Ionic gradients are necessary for the generation of the membrane potential. C. The size of the potential is proportional to the size of the ion gradient. D. The direction of the ion gradient determines the polarity of the membrane potential. E. For a given concentration gradient, the resulting potential is independent of the number of charges on the ion. - Correct Answer E. For a given concentration gradient, the resulting potential is independent of the number of charges on the ion. Calculate the equilibrium potential for Cl- given an intracellular concentration of 40 mM and an extracellular contration of 560 mM, as is typical for a squid neuron. - Correct Answer C. -0.066 mV action potentials are generated when - Correct Answer the cell reaches threshold Why was the voltage clamp critical to the ionic basis of the action potential? - Correct Answer because sodium and potassium currents are both time and voltage dependent, voltage clamping makes it possible to determine how each one contributes to the action potential 14. Which of the following does NOT stem from the application of Ohm's law to ionic conductances? A. The driving force on the ionic current is the difference between the membrane potential and the ion's Nernst potential. B. The conductance for an ion is inversely proportional to the resistance of the membrane to the passage of that ion. C. All permeant ions experience an identical driving force at each time point during the course of an action potential. D. The conductance for each ion can be calculated ba