Question 1: Which of the following best describes osmosis?

Answer: The movement of water molecules across a selectively permeable membrane

Question 2: True or False: Diffusion requires energy to move molecules across cell membranes.

Answer: False

Question 3: Define the term 'selectively permeable membrane'.

Answer: A membrane that allows certain molecules or ions to pass through it by means of active or passive transport.

Question 4: Match the following terms to their definitions:

Answer: See full answer key

Question 5: True or False: Osmosis can occur in both directions across a membrane.

Answer: True

Question 6: Explain the process of diffusion and give a real-life example.

Answer: Diffusion is the process of particles moving from an area of higher concentration to an area of lower concentration. An example is the exchange of oxygen and carbon dioxide between alveoli and blood in the lungs.

Question 7: Order the steps of osmosis in plant cells when placed in a hypotonic solution.

Answer: See full answer key

Question 8: Calculate the water potential in a cell given that the solute potential is -3.0 MPa and the pressure potential is 1.0 MPa. Use the formula: Water Potential = Solute Potential + Pressure Potential.

Answer: -2.0 MPa

Question 9: Fill in the blank: In osmosis, water moves from an area of _____ water potential to an area of _____ water potential.

Answer: higher; lower

Question 10: Discuss how the principles of osmosis and diffusion are essential for the survival of cells. Include examples to support your explanation.

Answer: Osmosis and diffusion are crucial for maintaining homeostasis in cells. They allow for the regulation of water and solute concentrations, enabling cells to obtain nutrients and expel waste. For example, in plant roots, osmosis allows water absorption, while diffusion facilitates gas exchange in leaves. In animal cells, diffusion is vital for oxygen uptake and carbon dioxide removal.

Question 11: Describe what happens to a red blood cell when placed in a hypertonic solution.

Answer: In a hypertonic solution, water leaves the red blood cell, causing it to shrink and become crenated.

Question 12: Which of the following is NOT a factor affecting the rate of diffusion?

Answer: Color of the solute

Question 13: Explain how facilitated diffusion differs from simple diffusion.

Answer: Facilitated diffusion requires the use of transport proteins to move molecules across cell membranes, while simple diffusion does not require proteins and occurs directly through the lipid bilayer.

Question 14: The movement of glucose into a cell against its concentration gradient requires...

Answer: Active transport

Question 15: What is the primary function of the semi-permeable cell membrane in osmosis?

Answer: To control the passage of water molecules into and out of the cell, maintaining the cell's internal environment.