Question 1

Which of the following best describes the process of facilitated diffusion across the plasma membrane?

Accepted Answer

Movement of solute down its concentration gradient with the help of a carrier or channel protein, without energy input.

Question 2

A red blood cell is placed in a 10% NaCl solution. What will happen to the cell, and what is the tonicity of the solution?

Accepted Answer

The cell will decrease in volume; the solution is hypertonic.

Question 3

Which of the following is an example of secondary active transport in the plasma membrane?

Accepted Answer

Using sodium ion gradient to bring glucose into the cell.

Question 4

During the action potential, which event occurs immediately after voltage-gated Na$^+$ channels inactivate?

Accepted Answer

Voltage-gated K$^+$ channels activate and repolarization begins.

Question 5

Which of the following best explains why ATP is required for primary active transport?

Accepted Answer

Solutes are moved against their concentration gradient, which requires energy input.

Question 6

A patient is given an intravenous solution of distilled water by mistake. What is the most likely effect on their red blood cells, and why?

Accepted Answer

Cells will swell and possibly burst because the solution is hypotonic.

Question 7

Which of the following is NOT a characteristic of simple diffusion?

Accepted Answer

Requires a transport protein.

Question 8

Which process is responsible for the uptake of cholesterol into cells?

Accepted Answer

Receptor-mediated endocytosis

Question 9

The Na$^+$/K$^+$ ATPase pump moves ions in which direction and in what ratio?

Accepted Answer

3 Na$^+$ out of the cell and 2 K$^+$ into the cell

Question 10

Which of the following best describes the role of the myelin sheath in a neuron?

Accepted Answer

It increases the speed of action potential conduction along the axon.

Question 11

Which of the following equations correctly represents the movement of water during osmosis?

Accepted Answer

$Water: Low \rightarrow High$ solute concentration

Question 12

A neuron is unable to return to its resting membrane potential after an action potential. Which channel is most likely malfunctioning?

Accepted Answer

Voltage-gated K$^+$ channel

Question 13

Which of the following is an example of exocytosis?

Accepted Answer

Release of neurotransmitters from a neuron into the synaptic cleft

Question 14

Which of the following best explains why glucose cannot cross the plasma membrane by simple diffusion?

Accepted Answer

Glucose is too large and polar to pass through the lipid bilayer without a transport protein.

Question 15

Which of the following best describes the function of the axon hillock in a neuron?

Accepted Answer

It is the site where action potentials are initiated.

Question 16

A cell is placed in an isotonic solution. What will happen to the cell volume, and why?

Accepted Answer

No change in cell volume because the concentration of solutes is equal inside and outside the cell.

Question 17

Which of the following is a key difference between phagocytosis and pinocytosis?

Accepted Answer

Phagocytosis engulfs large particles, while pinocytosis engulfs extracellular fluid.

Question 18

Which of the following best describes the direction of sodium and potassium movement during an action potential?

Accepted Answer

Na$^+$ moves into the cell during depolarization; K$^+$ moves out during repolarization.

Question 19

Which of the following best explains why the plasma membrane may hyperpolarize after an action potential?

Accepted Answer

K$^+$ channels remain open longer than needed, allowing excess K$^+$ to leave the cell.

Cell Membrane Transport and Neuronal Action Potentials: Study Notes

Study Guide - Practice Questions