Key term
Edexcel GCSE Biology 1BI0
Key Concepts in Biology
Topic overviewEukaryotic and prokaryotic cellsSpecialised cells and their adaptationsMicroscopes and magnification calculationsSize, scale and units in cell biologyEnzyme action and denaturationFactors affecting enzyme activityEnzymes in synthesis and digestion, and rate calculationsFood tests and the energy in foodDiffusion, osmosis and active transportOsmosis in potatoes and percentage change in mass
Cells and Control
Topic overviewMitosis and the cell cycleWhy mitosis matters: growth, repair and cancerGrowth, differentiation and percentile chartsStem cells and their use in medicineThe structure and function of the brainNeurones, receptors and the reflex arcThe structure and function of the eyeEye defects and how they are corrected
Genetics
Topic overviewAsexual and sexual reproductionMeiosis and the formation of gametesDNA structure, genes and the genomeExtracting DNA from fruitMendel's work and the inheritance of blood groupsAlleles, genotype and phenotypeMonohybrid crosses and sex determinationProbability and ratios from genetic crossesCauses of variation: genes and environmentThe Human Genome ProjectGenetic variation and the effects of mutation
Natural Selection and Genetic Modification
Topic overviewDarwin, Wallace and the theory of evolutionNatural selection and antibiotic resistanceFossil evidence for human evolutionStone tool evidence for human evolutionThe pentadactyl limb and the three domainsSelective breedingTissue cultureGenetic engineering and modern agricultureBenefits and risks of GM organisms
Health, Disease and the Development of Medicines
Topic overviewHealth, disease and susceptibilityPathogens and common infectionsHow pathogens spread, and the virus life cycleSexually transmitted infectionsHow plants defend themselvesPhysical barriers and chemical defencesThe immune system, immunisation and herd immunityAntibiotics and developing new medicinesAseptic technique in culturing microorganismsTesting antiseptics and antibiotics on bacterial culturesLifestyle factors and non-communicable diseaseTreatments for cardiovascular disease
Plant Structures and Their Functions
Topic overviewPhotosynthesis as an endothermic reactionLimiting factors in photosynthesisLight intensity and the rate of photosynthesisRoot hair cells, xylem and phloemTranspiration and translocationLeaf structure for photosynthesis and gas exchangeFactors affecting the rate of transpirationPlant adaptations to extreme environmentsPlant hormones, phototropism and gravitropism
Animal Coordination, Control and Homeostasis
Topic overviewHormones, endocrine glands and homeostasisThe menstrual cycle and its hormonesHormonal and barrier contraceptionHomeostasis and thermoregulationControlling blood glucose, and type 1 diabetesType 2 diabetes and body massThe urinary system and the production of ureaThe nephron, filtration and selective reabsorptionTreating kidney failure: dialysis and transplants
Exchange and Transport in Animals
Topic overviewWhy multicellular organisms need exchange surfacesAlveoli and gas exchangeRate of diffusion and Fick's lawThe blood and its componentsArteries, veins and capillariesThe heart and the circulatory systemCellular respiration as an exothermic reactionAerobic and anaerobic respiration comparedInvestigating the rate of respirationCardiac output, stroke volume and heart rate
Ecosystems and Material Cycles
Topic overviewLevels of organisation and interdependenceAbiotic and biotic factors in a communityParasitism and mutualismSampling with quadrats and transectsEstimating population size from field dataEnergy transfer between trophic levelsHuman impact on ecosystems and biodiversityFood securityThe carbon cycleThe water and nitrogen cyclesFactors affecting the rate of decompositionCalculating the rate of decay
Health, Disease and the Development of Medicines
How plants defend themselves
- 3 things to know
- Paper 1
Overview
Physical plant defences such as the waxy cuticle, cellulose cell wall, bark and layers of dead cells, how they differ from chemical defences, poisons and antibacterial chemicals that deter pests and pathogens, and plant chemicals such as quinine, salicylic acid and caffeine and why they are useful in medicine.
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Explain how the cell wall protects a plant cell from a pathogen.
Key term
Explain why damage to the bark of a tree increases the chance of infection.
Questions from this subtopic
Each one with the model answer underneath.
- 1
Name two physical barriers that protect a plant from pathogens.
Model answer
The waxy leaf cuticle and the cell wall.
- 2
Describe how the waxy cuticle of a leaf defends the plant.
Model answer
It forms a waterproof layer over the leaf surface that stops pathogens reaching the cells beneath.
- 3
Explain how the cell wall protects a plant cell from a pathogen.
Model answer
The cellulose wall is a tough barrier that a pathogen must break down before it can reach the cell contents.
- 4
Explain why damage to the bark of a tree increases the chance of infection.
Model answer
Bark is a physical barrier, so a wound gives pathogens direct access to the living tissue underneath.
- 5
Describe how a layer of dead cells around a stem helps to defend a plant.
Model answer
It forms a tough covering that pests and pathogens cannot easily penetrate, and it falls away carrying pathogens with it.
- 6
Explain how a physical barrier in a plant differs from a chemical defence.
Model answer
A physical barrier blocks pathogens from getting in, while a chemical defence kills or deters them once they arrive.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Health, Disease and the Development of Medicines, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.