Biology – Classification
All organism need to exchange substance, this is done via a number of
method; diffusion, osmosis or active transport.
In order for life process, such as respiration or photosynthesis to occur, certain
molecules need to enter organisms, such as water, oxygen or carbon dioxide.
These substances all enter or leave via the processes mentioned above.
As mentioned previously osmosis is the movement of water from an area of
high water concentration to an area of low water concentration across a
partially permeable membrane.
Diffusion is the passive movement of particles from an area of high
concentration to an area of low concentration; therefore in many ways
osmosis and diffusion are very similar.
However active transport is completely different. Active transport uses energy
to transport molecules from an area of low concentration to an area of high
concentration, therefore going in the opposite direction to diffusion and
For Excellence in tutoring contact our
> Effective Biology tutors
> Effective Biology Tutoring from professionals
> Online Biology tutors
> Help with Biology Assignment