The whole topic on one page. Each branch is one subtopic; read it out loud and try to explain every word.
Exchange and transport in animals
Transport and exchange
- Substances transportedOxygenCarbon dioxideWaterFood moleculesMineral ionsUrea
- Surface area : volume ratioSurface area ÷ volumeBigger organism, smaller ratio
- Single cellLarge ratioDiffusion enough
- MulticellularSmall ratioExchange surfaceTransport system
- AlveoliLarge surface areaOne cell thickMoist liningBlood supplyVentilation
Diffusion rateTriple only
- Surface areaTriple onlyLarger, faster
- Concentration gradientTriple onlySteeper, faster
- Diffusion distanceTriple onlyShorter, faster
- Fick’s lawTriple onlySA × conc. difference÷ thickness
Blood and vessels
- Red blood cellsHaemoglobinBiconcaveNo nucleus
- White blood cellsPhagocytes engulfLymphocytes: antibodies
- PlasmaCarries dissolved substances
- PlateletsClotting
- ArteriesThick wallElastic fibresHigh pressure
- VeinsValvesWide lumen
- CapillariesOne cell thickExchange
Heart and circulation
- Double circulationLungs circuitBody circuit
- Major vesselsVena cavaPulmonary arteryPulmonary veinAorta
- ValvesPrevent backflow
- Wall thicknessVentricles thickerLeft thicker than right
- Cardiac outputStroke volume × heart rate
Respiration
- ExothermicReleases energyMetabolic processes
- AerobicNeeds oxygenCO₂ + waterMore energy
- Anaerobic in animalsLactic acidLess energy
- Anaerobic in plants and yeastEthanol + CO₂
- Core practicalRespirometerSoda limeLiquid moves towards organisms