Question 1

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

Accepted Answer

A dynamic structure where phospholipids, proteins, and other molecules can move laterally, with various components embedded throughout.

Question 2

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

Accepted Answer

DNA replication

Question 3

A red blood cell is placed in a solution and begins to swell until it bursts. Which type of solution is the cell in, and what process is responsible for this outcome?

Accepted Answer

Hypotonic solution; osmosis

Question 4

Which of the following substances can diffuse directly across the plasma membrane without the help of membrane proteins?

Accepted Answer

Oxygen gas ($$O_2)$$

Question 5

Facilitated diffusion differs from simple diffusion in that:

Accepted Answer

Facilitated diffusion requires the assistance of membrane proteins.

Question 6

Which of the following best describes the difference between channel proteins and carrier proteins in facilitated diffusion?

Accepted Answer

Channel proteins provide a passageway for specific ions, while carrier proteins bind to and change shape to transport specific molecules.

Question 7

A plant cell is placed in a hypertonic solution. What is the most likely outcome?

Accepted Answer

The cell becomes plasmolyzed as it loses water.

Question 8

Which of the following statements about active transport is correct?

Accepted Answer

Active transport requires ATP to move substances against their concentration gradient.

Question 9

Which of the following best describes the difference between uniport and coupled transport (symport and antiport)?

Accepted Answer

Uniport moves one substance in one direction, while coupled transport moves two substances either in the same or opposite directions.

Question 10

A neuron relies on the sodium-potassium pump to maintain its resting potential. Which type of membrane transport is this, and what is the energy source?

Accepted Answer

Active transport; ATP

Question 11

Bulk transport is essential for which of the following cellular processes?

Accepted Answer

Moving large quantities of proteins or other macromolecules into or out of the cell

Question 12

Which of the following best explains why plant cells become turgid in a hypotonic solution?

Accepted Answer

Water enters the cell, and the cell wall prevents bursting, resulting in increased turgor pressure.

Question 13

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

Accepted Answer

Glucose entering a muscle cell via a GLUT transporter

Question 14

If a cell is placed in an isotonic solution, what will happen to the cell's volume over time?

Accepted Answer

The cell's volume will remain stable.

Question 15

Which of the following best describes osmosis?

Accepted Answer

The movement of water across a selectively permeable membrane from an area of low solute concentration to high solute concentration

Question 16

Which of the following is true regarding the normal osmotic conditions for animal and plant cells?

Accepted Answer

Animal cells thrive in isotonic solutions, while plant cells thrive in hypotonic solutions.

Question 17

Which of the following best explains the role of the cell wall in plant cells under hypotonic conditions?

Accepted Answer

It provides structural support, preventing the cell from bursting as water enters and turgor pressure increases.

Question 18

Which process is responsible for the uptake of large particles, such as bacteria, by white blood cells?

Accepted Answer

Bulk transport (phagocytosis)

Question 19

A scientist observes that a certain protein is only present on the outer surface of the plasma membrane. Which function is this protein most likely involved in?

Accepted Answer

Cell-cell recognition

Question 20

Which of the following scenarios best illustrates the concept of coupled transport (symport or antiport)?

Accepted Answer

A sodium ion and a glucose molecule are transported together into a cell.

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