diffusion, osmosis, active transport

Question 1

describe diffusion

Answer 1

-Diffusion is the movement of PARTICLES in any substance resulting in a net movement from an area of HIGH CONCENTRATION to an area of LOW CONCENTRATION.
-Substances such as oxygen and carbon dioxide may move in and out of cells by diffusion during gas exchange
The factors affecting it are:
-the TEMPERATURE
-the SURFACE AREA of the MEMBRANE
-the CONCENTRATION GRADIENT

Question 2

explain osmosis

Answer 2

The diffusion of water from a more dilute solution to a more concentrated solution through a partially permeable membrane.
-Water may move across cell membranes via osmosis

Question 3

define the term active transport

Answer 3

Active transport moves substances from a more dilute solution to a more concentrated solution
-This is against the concentration gradient and therefore requires energy from respiration
-allow mineral ions to be absorbed into plant root hairs from dilute solutions in the soil which they require for growth