The Movement Of Substances

Question 1

What is diffusion?

Answer 1

Diffusion is the movement of a substance from and area of ITS HIGH concentration TO an are of ITS LOW concentration.

Question 2

Example of diffusion in humans

Answer 2

O2 diffuses INTO (and CO2 diffuses OUT of) the blood in the lungs.

Question 3

Example of diffusion in plants

Answer 3

CO2 diffuses INTO (and O2 diffuses OUT of) the leaf (through stomata)

Question 4

What is osmosis?

Answer 4

Osmosis is the movement of water FROM an area of HIGH WATER concentration TO an area of LOW WATER concentration across a semi-permeable membrane.

Question 5

Definition of Plasmolysis

Answer 5

Plasmolysis is the pulling away of the cytoplasm from the cell wall due to the loss of water from the vacuole by osmosis.

Question 6

Effect of Plasmolysis on plants

Answer 6

Plants wilt

Question 7

Definition of Turgor (pressure)

Answer 7

Turgor is the outward pressure of the vacuole and cytoplasm against the plant cell wall.

Question 8

Effects of Turgor on plants

Answer 8

1) Herbaceous plants (that don’t have wood) such as lettuce and house plants rely on Turgor pressure for mechanical support.
2) Roots absorb water from the soil.