Question 1

Which of the following best describes the fluid mosaic model of the plasma membrane?

Accepted Answer

A flexible bilayer of phospholipids with embedded proteins that move and shift positions.

Question 2

Which component of the plasma membrane is primarily responsible for its selective permeability?

Accepted Answer

Phospholipid bilayer

Question 3

A red blood cell is placed in a solution and swells until it bursts. Which type of solution was it placed in?

Accepted Answer

Hypotonic

Question 4

Which of the following is a function of the glycocalyx on the cell surface?

Accepted Answer

Serving as a biological marker for cell recognition

Question 5

Which type of cell junction would you expect to find in tissues that experience significant mechanical stress, such as cardiac muscle?

Accepted Answer

Desmosomes

Question 6

A solution contains 1 M NaCl. What is its osmolarity?

Accepted Answer

$$2~	ext{osmol/L}$$

Question 7

Which of the following best explains why oxygen can diffuse directly through the plasma membrane?

Accepted Answer

Oxygen is a small, nonpolar molecule.

Question 8

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It uses carrier or channel proteins to move substances down their concentration gradient.

Question 9

If a cell is placed in a hypertonic solution, what will happen to the cell?

Accepted Answer

It will shrink due to water loss.

Question 10

Which of the following is a function of peripheral membrane proteins?

Accepted Answer

Acting as enzymes or providing structural support

Question 11

Which of the following best describes osmosis?

Accepted Answer

Movement of water from low solute concentration to high solute concentration

Question 12

Which of the following is true regarding the effect of temperature on diffusion rate?

Accepted Answer

Higher temperature increases diffusion rate.

Question 13

Which of the following is a real-life example of the importance of plasma membrane integrity?

Accepted Answer

In burn patients, loss of membrane integrity leads to uncontrolled loss of fluids and ions.

Question 14

Which of the following best explains why plant cells do not burst in hypotonic solutions, but animal cells do?

Accepted Answer

Plant cells have a rigid cell wall that limits hydrostatic pressure.

Question 15

Which of the following is a function of gap junctions?

Accepted Answer

Allowing rapid communication by permitting ions and small molecules to pass between cells

Question 16

A solution contains 0.5 M glucose and 0.5 M NaCl. What is the total osmolarity?

Accepted Answer

$$1.5~	ext{osmol/L}$$

Question 17

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

Accepted Answer

It increases membrane stability and fluidity.

Question 18

Which of the following is true about carrier-mediated facilitated diffusion?

Accepted Answer

It can become saturated when all carriers are occupied.

Question 19

Which of the following best explains why water can move through the plasma membrane despite being polar?

Accepted Answer

Water is small enough to pass through the lipid bilayer and also uses aquaporins.

Question 20

Which of the following is a consequence of a rapidly changing glycocalyx in cancer cells?

Accepted Answer

The immune system cannot recognize the cell as damaged, allowing it to replicate.

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

Study Guide - Practice Questions