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For an organism to function, substances must move into and out of cells. Three processes contribute to this movement - diffusion, osmosis and active transport.

Mitosis is cell division which produces two identical diploid cells for growth and repair. Differentiation occurs when cells become specialised. Stem cells can develop into different cell types.

Larger animals have a lower surface area to volume ratio. This means they need transport systems like our circulatory system and exchange surfaces like our lungs or fish gills.

During transpiration plants move water from the roots to their leaves for photosynthesis in xylem vessels. Glucose made in photosynthesis is then moved to all cells in phloem vessels for respiration.