Question 1: Define diffusion in the context of cell biology.

Answer: Diffusion is the passive movement of particles from an area of higher concentration to an area of lower concentration.

Question 2: Explain the mechanism by which diffusion occurs across a cell membrane.

Answer: Particles move down their concentration gradient through the cell membrane without using energy, until equilibrium is reached.

Question 3: Which types of molecules are most likely to diffuse through the cell membrane? Provide two examples.

Answer: Small, non-polar molecules such as oxygen and carbon dioxide.

Question 1: Calculate the rate of diffusion if 50 particles pass through a membrane in 10 seconds. Provide your answer in particles per second.

Answer: 5 particles per second

Question 2: If the concentration gradient of a substance is from 80 units to 20 units over a membrane 10 cm thick, what is the concentration difference per centimeter?

Answer: 6 units per centimeter

Question 1: Describe a simple experiment to demonstrate diffusion of a gas in the air. Include the variables that can affect the outcome and safety precautions.

Answer: See full answer key

Question 2: In an experiment measuring the diffusion of dye in water, what variables could be changed to observe their effect on the rate of diffusion?

Answer: See full answer key

Question 1: A student observes that a dye spreads throughout a glass of water in 5 minutes. If the temperature is increased, the dye spreads in 3 minutes. Explain how temperature affects the rate of diffusion.

Answer: Higher temperature increases particle movement, thus increasing the rate of diffusion.

Question 2: How does understanding diffusion help in industries such as medicine or food technology?

Answer: See full answer key