Question 1

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

Accepted Answer

A dynamic structure where proteins and lipids move freely within the bilayer, allowing selective permeability.

Question 2

Cholesterol is an important component of the plasma membrane. What is its primary function?

Accepted Answer

It stabilizes membrane fluidity by preventing extremes of rigidity and fluidity.

Question 3

Which of the following molecules can most easily cross the plasma membrane via simple diffusion?

Accepted Answer

O$$_2$$

Question 4

A cell is placed in a hypertonic solution. What will happen to the cell?

Accepted Answer

It will shrink as water leaves the cell.

Question 5

Which type of transport requires energy in the form of ATP?

Accepted Answer

Active transport

Question 6

The sodium-potassium pump is an example of which type of membrane transport?

Accepted Answer

Active transport

Question 7

Which equation best represents the net movement of water during osmosis?

Accepted Answer

$$\Delta \Psi = \Psi_{inside} - \Psi_{outside}$$

Question 8

Which of the following statements about facilitated diffusion is correct?

Accepted Answer

It uses transport proteins to move molecules down their concentration gradient.

Question 9

A red blood cell is placed in pure water. What is the expected outcome?

Accepted Answer

The cell will swell and may burst due to water influx.

Question 10

Which of the following best explains why ions such as Na$$^+$$ and K$$^+$$ require transport proteins to cross the plasma membrane?

Accepted Answer

They are charged and cannot pass through the hydrophobic core of the membrane.

Question 11

Which process involves the cell engulfing large particles or liquids by forming vesicles from the plasma membrane?

Accepted Answer

Endocytosis

Question 12

What is the main difference between exocytosis and endocytosis?

Accepted Answer

Exocytosis releases substances from the cell, while endocytosis brings substances into the cell.

Question 13

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

Accepted Answer

Providing structural support to the cell wall

Question 14

A cell uses the following equation to maintain ion gradients: $$[Na^+]_{out} \u003e [Na^+]_{in}$$ and $$[K^+]_{in} \u003e [K^+]_{out}. $$Which transport process is responsible for this?

Accepted Answer

Active transport via the sodium-potassium pump

Question 15

Which property of the plasma membrane allows it to be selectively permeable?

Accepted Answer

Arrangement of phospholipids and embedded proteins

Question 16

Which scenario best illustrates the concept of isotonic solution?

Accepted Answer

A cell placed in a solution with equal solute concentration as its cytoplasm.

Question 17

Which of the following is a consequence of placing a plant cell in a hypotonic solution?

Accepted Answer

The cell will gain water and become turgid.

Question 18

Which of the following best describes the role of transport proteins in the plasma membrane?

Accepted Answer

They facilitate the movement of specific molecules across the membrane.

Question 19

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

Accepted Answer

Red blood cells will swell and may burst due to water influx.

Question 20

Which of the following is a key factor that determines the rate of diffusion across the plasma membrane?

Accepted Answer

The size and polarity of the molecule

Study Notes: The Plasma Membrane (General Biology)

Study Guide - Practice Questions

Study Guide - Flashcards