AP®︎ Biology: Topic 2.7 Practice Test
Prepare for your quiz, test, or the AP exam with focused practice questions on Topic 2.7 of AP Biology – Tonicity and Osmoregulation.
Questions List
Topic 2.7
Question 1 Easy
This question tests the following: ENE-2.G
What type of transport is facilitated diffusion?
What You’re Being Tested On:
Explore the learning objectives taken directly from the College Board’s AP® Biology Curriculum. Ensure you’re prepared for the exact topics covered on the AP® exam, in-class tests, and quizzes, and gain confidence in your mastery of the material.
Topic 2.7: Tonicity and Osmoregulation
Learning Objective: 2.7.A
Explain how concentration gradients affect the movement of molecules across membranes.
Essential Knowledge: 2.7.A.1
External environments can be hypotonic, hypertonic, or isotonic to internal environments of cells. Movement of water can also be described as moving from hypotonic to hypertonic regions. Water moves by osmosis from regions of high water potential to regions of low water potential. Relevant Equation: Water potential: Ψ = Ψp + Ψs where: Ψp = pressure potential Ψs = solute potential. Illustrative examples: Contractile vacuole in protists; Central vacuole in plant cells.
Learning Objective: 2.7.B
Explain how osmoregulatory mechanisms contribute to the health and survival of organisms.
Essential Knowledge: 2.7.B.1
Growth and homeostasis are maintained by the constant movement of molecules across membranes.
Essential Knowledge: 2.7.B.2
Osmoregulation maintains water balance and allows organisms to control their internal solute composition and water potential. Water moves from regions of low osmolarity or solute concentration to regions of high osmolarity or solute concentration. Relevant Equation: Solute potential of a solution: Ψs = − iCRT where: i = ionization constant C = molar concentration R = pressure constant R = 0.0831 L·bar·mol⁻¹·K⁻¹ T = temperature in Kelvin (°C + 273).
