Diffusion in Multicellular Organisms (OCR GCSE Biology A, Combined (Gateway Science Suite)): Flashcards
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Practise the cards
13 cards from this deck
Main challenge of diffusion in large organisms
Main challenge of diffusion in large organisms
Distance - slow & inefficient over long distances
Surface area to volume ratio as organisms grow
Surface area to volume ratio as organisms grow
Volume increases faster than surface area
Examples of specialised diffusion structures
Examples of specialised diffusion structures
Lungs, gills, intestines
Why large surface area enhances diffusion
Why large surface area enhances diffusion
More area available for substances to diffuse across
Why thin membranes aid diffusion
Why thin membranes aid diffusion
Reduce distance, speeding up the process
Role of rich blood supply near exchange surfaces
Role of rich blood supply near exchange surfaces
Transports substances quickly to/from cells
How ventilation maintains diffusion in lungs
How ventilation maintains diffusion in lungs
Brings fresh O2, removes CO2, maintains gradient
Gas exchange in alveoli
Gas exchange in alveoli
O2 diffuses in, CO2 diffuses out of blood
Key features of alveoli aiding diffusion
Key features of alveoli aiding diffusion
Large surface area & thin walls
Structures in small intestine increasing surface area
Structures in small intestine increasing surface area
Villi & microvilli
Waste product removed by diffusion in kidneys
Waste product removed by diffusion in kidneys
Urea
Transport system complementing diffusion
Transport system complementing diffusion
Blood circulatory system
Processes where diffusion is integral
Processes where diffusion is integral
Respiration, nutrient uptake, waste removal