Diffusion Multiple Choice Questions

According to the definition provided, what is diffusion?

• The movement of particles from low to high concentration using energy.

• The net movement of particles from a region of their higher concentration to a region of their lower concentration.

• The random movement of water molecules across a cell membrane.

• The active transport of particles against a concentration gradient.

Diffusion is essential for life because it is the main way cells:

• Generate energy through physical processes.

• Get substances they need and get rid of waste products.

• Maintain a constant temperature.

• Create new particles in a beaker.

In the alveoli of the lungs, where is the concentration of oxygen higher, leading to diffusion into the blood?

• In the blood.

• In the alveoli.

• It is equal in both.

• In the carbon dioxide molecules.

For photosynthesis, a plant needs carbon dioxide from the air. How does this gas move into the leaf?

• Active transport.

• Osmosis.

• Respiration.

• Diffusion.

In the small intestine, nutrients move into the blood because:

• The blood has a high concentration of nutrient molecules.

• The gut has a low concentration of nutrient molecules.

• Nutrients are in high concentration in the gut and low concentration in the blood.

• The cell membrane actively pushes them into the blood.

Which of the following factors would increase the rate of diffusion?

• A smaller surface area.

• A lower temperature.

• A larger surface area.

• A longer distance for particles to travel.

How does a higher temperature lead to a faster rate of diffusion?

• It decreases the kinetic energy of particles.

• It gives particles more kinetic energy.

• It makes the concentration gradient smaller.

• It increases the distance particles must travel.

A steeper concentration gradient means:

• A slower rate of diffusion.

• A faster rate of diffusion.

• No change in the rate of diffusion.

• The particles stop moving.

The movement of particles during diffusion is described as being a result of their:

• Directed movement.

• Magnetic attraction.

• Random movement.

• Electrical charges.

Which factor would cause the rate of diffusion to decrease?

• A steep concentration gradient.

• A short distance for particles to travel.

• A high temperature.

• A small surface area.