Diffusion

Question 1

Describe molecules.

Answer 1

Solids, liquids and gases are made up from small particles called molecules. In liquids and gases the molecules move freely. In solids the molecules are not as free to move.

Question 2

What is the definition of diffusion?

Answer 2

Diffusion is the movement of molecules from a region of higher concentration of the molecule to a region of lower concentration, i.e down a concentration gradient.

Question 3

What is diffusion an example of?

Answer 3

Diffusion is an example of passive transport. (it does not require energy)

Question 4

What does a concentration gradient mean?

Answer 4

A concentration gradient is just a difference between concentrations i.e. one concentration is higher than the other.

Question 5

What is the importance of diffusion to cells?

Answer 5

Cells require glucose and oxygen to diffuse into them so they can make energy during a process called aerobic respiration. During this respiration process, cells make the waste product,carbon dioxide , which must diffuse out of the cells so they can stay alive.

Question 6

Explain why diffusion is important to multicellular animals.

Answer 6

Blood returning to the lungs from respiring cells contains a higher concentration of carbon dioxide and a lower concentration of oxygen than the air in the air sac. Carbon dioxide therefore diffuses out the blood and oxygen diffuses in.

Question 7

Why does oxygen diffuse from an alveolus in the lungs to a blood capillary?

Answer 7

The oxygen concentration in the alveolus is greater than in the blood.

Question 8

Why does oxygen diffuse from the air into the water before reaching the fish?

Answer 8

Oxygen is more concentrated in the air than in the water.