Pre AP Biology -CELLS 3.2 Cell Transport- MCQ Exam Style Questions -New Syllabus

Pre AP Biology -CELLS 3.2 Cell Transport- MCQ Exam Style Questions – New Syllabus 2025-2026

Pre AP Biology -CELLS 3.2 Cell Transport- MCQ Exam Style Questions – Pre AP Biology – per latest Pre AP Biology Syllabus.

Pre AP Biology – MCQ Exam Style Questions- All Topics

Question

Which of these statements best describes water potential?

a. the driving force for the potential osmotic movement of water into plant cells

b. a measure of the combined effects of a solution’s pressure potential and its solute potential

c. the force that is less negative in a solution that has more solute molecules relative to water molecules

d. a measure of the potential physical pressure required to halt osmotic water movement across a membrane

▶️ Answer/Explanation

Detailed solution

The correct option is b.
Water potential ($\Psi$) is defined by the equation $\Psi = \Psi_s + \Psi_p$.
It quantifies the tendency of water to move from one area to another.
$\Psi_s$ represents the solute potential, which lowers water potential as solutes are added.
$\Psi_p$ represents the pressure potential, which is the physical pressure on a solution.
Together, these two components dictate the overall free energy of water in a system.
Therefore, it is best described as the combined effect of these two physical properties.

Question

Which of the following best describes turgor pressure?

a. The force equivalent to water’s potential pressure
b. The pressure of the movement of water into a cell by osmosis
c. The driving force for osmotic movement of water
d. The pressure exerted by fluid inside a plant cell against the cell wall

▶️ Answer/Explanation

Correct Option: d

Detailed solution:

Turgor pressure is the hydrostatic pressure generated within a cell.
It occurs as the central vacuole fills with water via osmosis.
The expanding protoplast pushes outward against the rigid cell wall.
This internal pressure provides structural rigidity to non-woody plants.
In the water potential equation, it is represented as pressure potential ($\psi_p$).
Option d accurately identifies this physical interaction between fluid and the wall.

Question

An ion moving through a membrane channel in one direction gives energy to actively transport another molecule in the opposite direction. Which of these processes does this describe?

a. cotransport
b. symport transport
c. exchange diffusion
d. facilitated diffusion

▶️ Answer/Explanation

Detailed solution

The correct answer is a. cotransport (specifically antiport).
This process is a form of secondary active transport.
One ion moves down its electrochemical gradient, releasing free energy.
This energy is used to pump a second substance up its gradient.
Since the substances move in opposite directions, it is called antiport.
Both symport and antiport are sub-categories of cotransport.
Facilitated diffusion is ruled out as it does not require an energy input.

Pre AP Biology -CELLS 3.2 Cell Transport- MCQ Exam Style Questions -New Syllabus