Question 1

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

Accepted Answer

It provides structural support, regulates transport, communicates with other cells, and identifies the cell.

Question 2

A red blood cell is placed in a hypotonic solution. What is the most likely outcome, and why?

Accepted Answer

The cell will swell and may burst because water enters the cell due to osmosis.

Question 3

Which of the following is NOT a component of the cytoplasm?

Accepted Answer

Nucleus

Question 4

Which process is responsible for the movement of oxygen and carbon dioxide across the plasma membrane?

Accepted Answer

Simple diffusion

Question 5

The sodium-potassium pump ($$Na^+/K^+$$ ATPase) moves ions across the plasma membrane. Which of the following correctly describes its action?

Accepted Answer

It moves 3 $$Na^+$$ ions out of the cell and 2 $$K^+$$ ions into the cell using ATP.

Question 6

Which of the following best explains why the phospholipid bilayer forms the basic structure of the plasma membrane?

Accepted Answer

Phospholipids have hydrophilic heads and hydrophobic tails, causing them to arrange into a bilayer with heads facing water and tails facing inward.

Question 7

A patient is given an intravenous solution that is hypertonic relative to their red blood cells. What will happen to the cells?

Accepted Answer

They will shrink and crenate as water leaves the cells.

Question 8

Which of the following is a function of membrane proteins that distinguishes them from phospholipids?

Accepted Answer

Acting as channels, carriers, receptors, enzymes, and providing structural support

Question 9

Which type of transport requires energy directly from ATP hydrolysis to move substances against their concentration gradient?

Accepted Answer

Primary active transport

Question 10

Which of the following best describes the process of exocytosis?

Accepted Answer

The cell releases substances by fusing a vesicle with the plasma membrane, expelling its contents into the extracellular fluid.

Question 11

Which of the following scenarios best illustrates secondary active transport?

Accepted Answer

A sodium-glucose symporter uses the $$Na^+$$ gradient established by the $$Na^+/K^+$$ pump to bring glucose into the cell against its gradient.

Question 12

Which of the following statements about osmosis is correct?

Accepted Answer

Osmosis is the movement of water across a selectively permeable membrane from an area of lower solute concentration to higher solute concentration.

Question 13

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

Accepted Answer

It stabilizes the membrane structure during temperature changes.

Question 14

A cell is placed in an isotonic solution. What will happen to the cell?

Accepted Answer

It will remain the same size because there is no net movement of water.

Question 15

Which of the following is a property of integral (transmembrane) proteins?

Accepted Answer

They span the entire width of the membrane and can act as channels or carriers.

Question 16

Which of the following best describes the difference between simple diffusion and facilitated diffusion?

Accepted Answer

Simple diffusion moves nonpolar molecules directly through the bilayer, while facilitated diffusion requires membrane proteins for polar or charged molecules.

Question 17

Which of the following is a real-life example of phagocytosis?

Accepted Answer

A white blood cell engulfing a bacterium.

Question 18

Which of the following best describes the resting membrane potential of a typical cell?

Accepted Answer

The cytosol is approximately -80 mV compared to the extracellular fluid.

Question 19

Which of the following is a function of the cytoskeleton?

Accepted Answer

Supporting the cell, maintaining its shape, and holding organelles in place

Question 20

Which of the following best describes transcytosis?

Accepted Answer

A continuous pathway combining endocytosis, internal transport, and exocytosis to move substances across a cell.

Chapter 3: The Cell – Structure, Function, and Membrane Transport

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