Question 1

Which of the following best describes the structure of the plasma membrane in eukaryotic cells?

Accepted Answer

A phospholipid bilayer with embedded proteins and cholesterol

Question 2

What is the primary function of cholesterol in the plasma membrane?

Accepted Answer

To increase the strength and rigidity of the cell membrane

Question 3

A red blood cell is placed in a hypertonic solution. What will happen to the cell, and why?

Accepted Answer

It will shrink (crenate) because water moves out of the cell

Question 4

Which type of embedded protein in the plasma membrane is responsible for cell-to-cell recognition?

Accepted Answer

Glycoprotein

Question 5

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

It uses membrane proteins to transport specific molecules

Question 6

Which equation best represents the movement of water during osmosis across a selectively permeable membrane?

Accepted Answer

$$Water: High \rightarrow Low$$

Question 7

The sodium-potassium pump is an example of active transport because:

Accepted Answer

It requires the breakdown of ATP to function

Question 8

Which process is used by cells to import large molecules such as insulin?

Accepted Answer

Endocytosis

Question 9

A patient receives an intravenous solution that is hypotonic compared to their blood plasma. What is the most likely effect on their red blood cells?

Accepted Answer

Cells will swell and may burst due to water influx

Question 10

Which of the following is NOT a passive transport method across the plasma membrane?

Accepted Answer

Endocytosis

Question 11

A gated channel protein in the plasma membrane will:

Accepted Answer

Open only when triggered by specific signals or conditions

Question 12

Which of the following best explains why oxygen and carbon dioxide can easily cross the plasma membrane?

Accepted Answer

They are small, uncharged, and non-polar molecules

Question 13

Which formula correctly represents the direction of solute movement during diffusion?

Accepted Answer

$$High \rightarrow Low$$

Question 14

A cell uses exocytosis to:

Accepted Answer

Export products and remove toxic wastes

Question 15

Which of the following scenarios best illustrates the concept of selective permeability of the plasma membrane?

Accepted Answer

Water and small non-polar molecules pass freely, while ions require specific channels

Question 16

Which of the following is a correct multi-step sequence for the movement of glucose into a cell?

Accepted Answer

Glucose binds to a transport protein, protein changes shape, glucose is released inside the cell

Question 17

If a cell is placed in an isotonic solution, what will happen to its volume?

Accepted Answer

It will remain unchanged because water movement is balanced

Question 18

Which of the following statements about active transport is TRUE?

Accepted Answer

It requires energy, often from ATP, to move molecules against their concentration gradient

Question 19

A cell needs to quickly remove a large quantity of waste products. Which process will it most likely use?

Accepted Answer

Exocytosis

Question 20

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

Accepted Answer

Glucose entering most cells via a carrier protein

The Plasma Membrane and Movement Across It: Structure, Function, and Transport Mechanisms

Study Guide - Practice Questions