Question 1

Which of the following best describes the function of the plasma membrane in a generalized cell?

Accepted Answer

It acts as a flexible outer boundary, controlling what enters and exits the cell.

Question 2

A patient is suffering from severe burns that damage the plasma membranes of their cells. Which of the following is the most likely consequence?

Accepted Answer

Substances will diffuse freely into and out of the cell, compromising concentration gradients.

Question 3

Which equation best represents the relationship between the rate of diffusion ($$R) $$and the concentration gradient ($$\Delta C) $$across a membrane?

Accepted Answer

$$R = k \cdot \Delta C$$

Question 4

Which of the following statements about membrane lipids is correct?

Accepted Answer

Phospholipid heads are hydrophilic and face the aqueous environment.

Question 5

A cell is placed in a solution with a higher concentration of solutes than its cytoplasm. What process will occur, and what is the direction of water movement?

Accepted Answer

Osmosis; water will move out of the cell.

Question 6

Which type of membrane protein is most likely to function as a channel for ions to pass through the plasma membrane?

Accepted Answer

Integral protein

Question 7

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

Facilitated diffusion uses membrane proteins to transport substances across the membrane.

Question 8

Which of the following best describes the role of cholesterol in the plasma membrane?

Accepted Answer

It increases membrane fluidity and flexibility.

Question 9

Which of the following is a correct statement about passive transport across the plasma membrane?

Accepted Answer

Passive transport moves substances down their concentration gradient without energy input.

Question 10

A scientist observes that increasing the temperature of a solution increases the rate of diffusion of a solute across a membrane. Which equation best explains this relationship?

Accepted Answer

$$R = k \cdot T$$

Question 11

Which of the following is NOT a function performed by membrane proteins?

Accepted Answer

Providing genetic information for the cell

Question 12

Which of the following best describes the concept of selective permeability in the plasma membrane?

Accepted Answer

The membrane allows certain substances to enter or exit while preventing others.

Question 13

Which of the following is a real-world example of facilitated diffusion?

Accepted Answer

Glucose entering muscle cells via a specific carrier protein.

Question 14

Which of the following extracellular fluids is found surrounding nervous system organs?

Accepted Answer

Cerebrospinal fluid

Question 15

Which of the following best explains why phospholipids form bilayers in water?

Accepted Answer

Phospholipid heads are hydrophilic and tails are hydrophobic.

Question 16

Which of the following is true regarding integral membrane proteins?

Accepted Answer

They are inserted into the membrane and span its entire width.

Question 17

A cell is exposed to a toxin that blocks all channel proteins in its plasma membrane. Which process will be most directly affected?

Accepted Answer

Facilitated diffusion of ions

Question 18

Which of the following best describes the movement of water across a selectively permeable membrane?

Accepted Answer

Osmosis

Question 19

Which of the following is a correct statement about cell diversity in humans?

Accepted Answer

There are over 250 different types of human cells, each with specialized functions.

Cells: The Living Units – Structure and Function of the Plasma Membrane

Study Guide - Practice Questions

Study Guide - Flashcards