Back to revision notes Open full-size SVG Print mind map CB2 Cells and control mind map Use your browser’s Print command for A4 landscape, or choose A3 in its paper settings. The SVG remains sharp when enlarged. A text version follows the map.
Read the mind map as text Cell division Purpose: Growth / repair / replacement; asexual clonesPreparation: Interphase: grow and copy DNA into sister chromatidsAlignment: Prophase: spindle; metaphase: equatorSeparation: Anaphase: chromatids separate; telophase: two nucleiOutcome: Cytokinesis → two cells; chromosome number maintainedCancer: Uncontrolled division can produce a tumourGrowth Increase: Animals grow through division and differentiationPercentage: Change ÷ initial × 100; 20 g → 25 g gives 25%Percentiles: Compare age with reference size; 50th = medianInterpretation: 75th: 75% smaller in reference; assess trendsStem cells Differentiation: Unspecialised → structures for particular jobsPotential: Stem cells divide and differentiateTypes: Embryonic: most types; adult: limited rangeTreatment: Replace cells; established and researched usesRisks: Tumours, infection and rejection require testingEthics: Embryo destruction versus treatment benefitsPlant growth Meristems: Root / shoot division → elongation → differentiationXylem: Dead hollow vessels: water / minerals upwardsRoot hairs: Large area and thin wall support uptakeEntry: Water: osmosis; mineral ions: active transportNerve signals Organisation: CNS: brain and spinal cord; peripheral nerves link bodyRoute: Stimulus → receptor → sensory → relay → motor → effectorEffectors: Muscles contract; glands secreteNeurones: Dendrites receive; axon carries impulses to terminalsMyelin: Insulates the axon and speeds signalsSynapses: Chemical across gap; electrical along neuronesRapid responses Reflex: Automatic protection; no conscious decision requiredArc: Sensory → spinal relay → motor → muscleReaction time: Ruler drop: voluntary response, not impulse speedMethod: Unannounced drop; catch; table converts distanceReliability: Repeat, mean; same hand position / distractionsConnections Cell division → Growth: Mitosis supplies cells for growth. Nerve signals → Rapid responses: Reflex arcs use sensory, relay and motor neurones. 