2.16 describe experiments to investigate diffusion and osmosis using living and non-living systems

Diffusion
Put a coloured substance (like food colouring) into a clear one (like water)
Time how long it takes for all the liquid to be the same colour.
Change the temperature of the liquid and make observations.
The higher the heat, the more kinetic energy meaning the colour moves through the liquid faster.

Osmosis
Cut two roughly equal pieces of potato and weigh them.
Put one in distilled water and one in salt water.
After a given amount of time weigh them.
The one in salt water will have lost mass as the water in the potato moves to the more highly concentrated salt water. Where as in the pure water the potato will have gained mass as it was less dens with water.

2.15 understand the factors that affect the rate of movement of substances into and out of cells, to include the effects of surface area to volume ratio, temperature and concentration gradient

Surface area
with a larger surface area- molecules have more surfaces through which to diffuse, this increases the rate of moment

Temperature
Increased temperature means increased kinetic energy- this will mean molecules collide with the cell membrane more often making movement through it more likely

Concentration gradient
This is the difference between the concentration inside and outside of the cell. The bigger the difference is the more opportunity molecules have of diffusing.

2.14 understand the importance in plants of turgid cells as a means of support

A turgid cell is one that is, effectively, full of water; this increases the volume of the cytoplasm, which exerts pressure outwards. These cells are stronger so they support the plant- meaning that a plant grows upwards.

This is why a dehydrated plant will wilt.

2.13 understand that movement of substances into and out of cells can be by diffusion, osmosis and active transport

These three processes (defined in 2.12) are the ways in which substances move in and out of cells.

This video explains how:

http://www.youtube.com/watch?feature=player_embedded&v=BN1m5OThsJE

2.12 understand definitions of diffusion, osmosis and active transport

Diffusion is when molecules move from a area of high concentration to a area of low concentration

Osmosis is the movement of water, it follows the rule that water will move from a dilute solution to a concentrated solution.

Active transport is molecules being moved from an area of low concentration to an area of high concentration  energy is needed to make this happen hence 'active'