1.3.1 Diffusion

• Why is diffusion of carbon dioxide into leaf cells significant?

  Sustains photosynthesis
• The driving force for diffusion is a water potential gradient.

  False
• Both diffusion and osmosis occur down a concentration gradient without energy.


  True
• Match the aspect of diffusion with its description:

  Definition ↔️ Movement of molecules from high to low concentration

  Energy Requirement ↔️ No external energy required

  Outcome ↔️ Concentration becomes equal throughout
• Particles in diffusion move randomly but collectively disperse from high to low concentration down a gradient
• A steeper concentration gradient leads to slower diffusion.

  False
• A larger surface area facilitates more diffusion because there is more space for particles to move
• What is the direction of particle movement in diffusion?

  High to low concentration
• Smaller particles diffuse faster than larger particles.


  True
• Diffusion requires external energy input.

  False
• Diffusion requires external energy input.

  False
• What drives the movement of particles in diffusion?

  Concentration gradient
• How does a steeper concentration gradient affect diffusion rate?

  Increases diffusion rate
• What type of surface area facilitates more diffusion?

  Larger surface area
• Higher temperatures increase particle kinetic energy
• In the lungs, which gas diffuses from the alveoli into the blood?

  Oxygen
• Diffusion requires external energy to occur.

  False
• Higher temperatures increase particle kinetic energy, accelerating diffusion.
• Smaller particles diffuse more quickly than larger particles.

  True
• Arrange the steps in the exchange of oxygen and carbon dioxide in the alveoli:

  1️⃣ Oxygen moves from the air into the blood

  2️⃣ Carbon dioxide moves from the blood into the air
• How does temperature affect the rate of diffusion?

  Increases the rate
• The definition of diffusion is the movement of molecules from high to low concentration
• What is the definition of diffusion?

  Movement from high to low concentration
• The outcome of diffusion is that concentration becomes equal
• Rank the factors affecting diffusion rate from most to least impact.

  1️⃣ Temperature

  2️⃣ Concentration Gradient

  3️⃣ Surface Area

  4️⃣ Size of Particles
• Smaller particles diffuse more quickly than larger particles.


  True
• Give an example of diffusion in biological systems.

  Gas exchange in lungs
• A larger surface area decreases the rate of diffusion.

  False
• Which process in the small intestine depends on diffusion?

  Nutrient uptake
• What is the primary difference between diffusion and osmosis?

  Osmosis moves water
• Osmosis requires a semi-permeable membrane.