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

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

Question 2: Explain why diffusion is considered a passive process in cells.

Answer: Diffusion is passive because it does not require energy; particles move naturally down their concentration gradient.

Question 3: What factors influence the rate of diffusion? List at least three.

Answer: Concentration gradient, temperature, particle size, and surface area of the membrane.

Question 4: Describe a practical example of diffusion in everyday life.

Answer: The smell of perfume spreading through a room is an example of diffusion.

Question 5: Calculate the diffusion rate if 50 particles pass through a membrane in 10 seconds. (Rate = particles/time)

Answer: 5 particles per second

Question 6: Multiple Choice: Which of the following factors would decrease the rate of diffusion?

Answer: Decrease in concentration gradient

Question 7: Fill in the blank: Diffusion occurs until __________ is reached, meaning particles are evenly distributed.

Answer: equilibrium

Question 8: Describe a scientific experiment to observe diffusion across a membrane. Include variables to control and safety precautions.

Answer: Students can place a drop of dye in water separated by a semi-permeable membrane and observe the dye spreading over time. Controlled variables include temperature, dye concentration, and solution volume. Safety precautions involve handling dyes carefully and wearing protective gloves and eye protection.

Question 9: In a scenario where a high concentration of sugar solution is in contact with a cell membrane, explain what happens to the water molecules on both sides.

Answer: Water molecules will move from the side with lower sugar concentration (higher water concentration) to the side with higher sugar concentration (lower water concentration) to balance the concentration, leading to osmosis.

Question 10: Apply your understanding of diffusion to explain how oxygen enters the blood from the lungs.

Answer: Oxygen diffuses from the alveoli in the lungs, where its concentration is high, into the blood capillaries, where its concentration is lower. This movement occurs passively along the concentration gradient, enabling efficient gas exchange vital for respiration.