Question 1

Which of the following best describes simple diffusion across a cell membrane?

Accepted Answer

Movement of small, nonpolar molecules directly through the lipid bilayer from high to low concentration without energy input.

Question 2

Which factor does NOT directly affect the rate of diffusion across a membrane?

Accepted Answer

Type of vesicle used

Question 3

A red blood cell is placed in a hypotonic solution. What will most likely happen to the cell?

Accepted Answer

It will swell as water enters the cell.

Question 4

Which of the following is an example of facilitated diffusion?

Accepted Answer

Glucose entering a cell through a carrier protein.

Question 5

What is the main energy source for primary active transport?

Accepted Answer

ATP hydrolysis

Question 6

Which of the following best describes osmosis?

Accepted Answer

Diffusion of water across a semipermeable membrane from an area of low solute concentration to high solute concentration.

Question 7

Which process is responsible for engulfing large particles, such as bacteria, into a cell?

Accepted Answer

Phagocytosis

Question 8

A cell uses a sodium-potassium pump to move sodium ions out and potassium ions in. Which type of transport is this?

Accepted Answer

Primary active transport

Question 9

Which of the following statements about vesicular transport is TRUE?

Accepted Answer

Exocytosis releases substances from the cell by fusion of vesicles with the plasma membrane.

Question 10

Which equation best represents the direction of diffusion for a solute across a membrane?

Accepted Answer

$$ J = -D \frac{dC}{dx} $$

Question 11

Which of the following is NOT a characteristic of passive transport?

Accepted Answer

Requires ATP hydrolysis

Question 12

A cell is placed in an isotonic solution. What will happen to the cell's volume over time?

Accepted Answer

It will remain unchanged as water moves in and out at equal rates.

Question 13

Which of the following best explains why water can cross the lipid bilayer despite being polar?

Accepted Answer

Water is small enough to pass through the membrane, and also uses aquaporins for facilitated diffusion.

Question 14

Which scenario best illustrates receptor-mediated endocytosis?

Accepted Answer

A cell takes in cholesterol by binding it to specific membrane receptors before internalizing it.

Question 15

Which of the following is a key difference between facilitated diffusion and active transport?

Accepted Answer

Facilitated diffusion does not require energy, while active transport does.

Question 16

A cell is exposed to a toxin that inhibits ATP production. Which transport process would be most directly affected?

Accepted Answer

Primary active transport

Question 17

Which of the following best describes pinocytosis?

Accepted Answer

The cell membrane folds in to engulf small amounts of extracellular fluid.

Question 18

Which of the following is NOT a function of vesicular transport?

Accepted Answer

Facilitated diffusion of glucose

Question 19

Which of the following statements about the sodium-potassium pump is correct?

Accepted Answer

It moves sodium ions out of the cell and potassium ions into the cell against their concentration gradients using ATP.

Question 20

Which of the following best describes the movement of water in a hypertonic solution?

Accepted Answer

Water moves out of the cell, causing it to shrink.

Membrane Transport Mechanisms: Passive and Active Transport

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