IGCSE›Oxford AQA IGCSE Biology›Mind mapsPrinciples of organisationOxford AQA IGCSE Biology: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsLevelsCell is the basic unit of lifeTissue: similar cells, one functionOrgan: different tissues working togetherOrgan system: organs sharing a major processOrganism: all systems togetherSpecialised cellsRed blood cell: biconcave, no nucleus, haemoglobinSperm: tail, acrosome, mitochondriaRoot hair: long extension, big surface areaPalisade: tall, packed with chloroplastsNeurone: long axon, branched dendritesAnimal tissuesEpithelial covers surfaces and lines organsConnective binds and supports: blood, boneNervous transmits electrical signalsMuscle contracts: skeletal, cardiac, smoothOrganisationcells to organismscelltissueorganPlant tissuesDermal protects: epidermis, cuticleGround: palisade and spongy mesophyllXylem carries water and minerals upPhloem carries dissolved sugarsOrgans: leaf, stem, rootOrgan systemsCirculatory: heart, vessels, bloodRespiratory: lungs, gas exchangeDigestive: breaks down and absorbs foodNervous is fast, endocrine is slowExam tipsLink structure to function in every answerCilia are short and many; flagella long and singleUse 'this allows…' to show the link