Diffusion and Osmosis

Question 1

What does selectively permeable membrane mean?

Answer 1

Selectively permeable membrane means that it allows some but not all substances to pass through

Question 2

What does diffusion mean?

Answer 2

Diffusion is the spreading out of molecules from a region of high concentration to a region of low concentration.

Question 3

What does osmosis mean?

Answer 3

Osmosis is the movement of water molecules from a region of higher water concentration to a region of lower water concentration across a semi-permeable membrane.

Question 4

What is amoeba?

Answer 4

It survives in a less concentrated environment because of its contractile vacuole, which eliminates water.

Question 5

What happens to the animal cell when the environment is less concentrated?

Answer 5

• The cytoplasm gains water and then swells and bursts.

Question 6

What happens to the animal cell when the environment is more concentrated?

Answer 6

• The cytoplasm loses water, shrivels and then can die.

Question 7

What happens to plant cells when the environment is less concentrated?

Answer 7

• The cytoplasm gains water and becomes turgid and strong.

Question 8

What happens to the plant cell when the environment is more concentrated?

Answer 8

The cytoplasm loses water and becomes weak.

Question 9

What can high salt and sugar concentrations be used as?

Answer 9

1. Can be used to remove water from micro-organisms by osmosis.
2. Are used as food preservation techniques.

Question 10

What is the term turgor/ turgor pressure mean?

Answer 10

Is the outward pressure of the cytoplasm and vacuole against the cell wall of a plant.