B1 EXCHANGE SURFACES

EXCHANGE SURFACES

• Cells use diffusion to take in substances they need and get rid of waste products
• The larger an organism is, the smallers in surface area:volume ratio
• In SINGLE-CELLED organisms, gases and dissolved substances can diffuse directly into/out of the cell across the cell membrane, they have a large surface area:volume ratio, so enough substances can be exchanged across the cell membrane to supply the volume of…