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Description
Gas exchange in simple
unicellular organisms
1 The cell membrane is the site of gas exchange
2 Example of a unicellular org
2.1 Amoeba
3 Where do they live
3.1 Live in water and diffusion of gases occurs over the whole body surface
4 They have:
4.1 A large surface area to volume ratio
4.2 Their membranes are thin and moist
4.3 Short diffusion pathways
4.4 Are small and need to be small in order for
diffusion to be efficient
5 How they become larger
5.1 Aggregate their cells together
6 The process of diffusion is slow
6.1 WHY?
6.1.1 Materials need to be exchanged between
different organs as well as the environment