Key term
AQA GCSE Biology 8461
Bioenergetics
Cell Biology
Topic overviewEukaryotes and prokaryotesAnimal and plant cellsCell specialisation and differentiationMicroscopyGrowing bacteria and aseptic techniqueCalculating bacterial growth, and testing antiseptics and antibioticsChromosomes, mitosis and the cell cycleStem cells in embryos, adults and meristemsTherapeutic cloning, its risks, and cloning plantsDiffusion and the factors affecting its rateSurface area to volume ratio and exchange surfacesOsmosisActive transport
Ecology
Topic overviewLevels of organisation in an ecosystem, and what organisms needCompetition, interdependence and stable communitiesAbiotic factorsBiotic factorsAdaptationsProducers, food chains and sampling with quadrats and transectsPredators, prey and measuring population sizeHow materials are cycledDecompositionWaste management and biodiversityLand use, deforestation and global warmingMaintaining biodiversityTrophic levels and pyramids of biomassTransfer of biomassFactors affecting food securityFarming techniques and sustainable fisheriesRole of biotechnology
Homeostasis and Response
Topic overviewHomeostasisThe nervous system and the reflex arcThe structure of the eye and accommodationMyopia, hyperopia and how they are correctedThe brain and the control of body temperatureHuman endocrine systemInsulin, glucagon and diabetesWater and ion loss, and the production of ureaThe kidneys, ADH and treating kidney failureHormones in human reproductionContraceptionPlant hormones and their uses
Infection and Response
Inheritance, Variation and Evolution
Topic overviewSexual and asexual reproductionMeiosisAdvantages and disadvantages of sexual and asexual reproductionDNA and the genomeDNA as a polymer of four nucleotidesGenetic terms, dominant and recessive allelesPunnett squares, probability and genetic crossesInherited disorders and sex determinationVariationEvolutionSelective breedingWhat genetic engineering is, and what it is used forGM crops, their risks, and the steps of the processCloningDarwin, Lamarck and the acceptance of evolutionSpeciationThe understanding of geneticsEvidence for evolution, and extinctionFossilsResistant bacteriaClassification of living organisms
Organisation
Topic overviewLevels of organisation, and how enzymes workAmylase, proteases and lipasesBile, food tests and the effect of pH on amylaseThe heart, the lungs and double circulationThe pacemaker, the blood vessels and the bloodCoronary heart disease: a non-communicable diseaseHealth issuesRisk factors and causal mechanisms in diseaseSampling, correlation and interpreting risk dataCancerPlant tissues, and transpiration and its rateRoot hair cells, xylem, phloem and stomata
Cell Biology
Microscopy
- 3 things to know
- Paper 1
Overview
Magnification and resolution, how electron microscopes compare with light microscopes and what they revealed about sub-cellular structures, and calculating magnification, image size and real size, including conversion to micrometres and standard form.
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
What is meant by the resolution of a microscope?
Key term
Which property limits how much detail can be seen, magnification or resolution?
Questions from this subtopic
Each one with the model answer underneath.
- 1
What is meant by the magnification of a microscope?
Model answer
How many times larger the image is than the real object.
- 2
What is meant by the resolution of a microscope?
Model answer
The smallest distance between two points that can still be seen as separate, which sets how much detail is visible.
- 3
Which property limits how much detail can be seen, magnification or resolution?
Model answer
Resolution, because magnifying further only makes a blurred image bigger.
- 4
Compare an electron microscope with a light microscope.
Model answer
An electron microscope has much higher magnification and much higher resolving power.
- 5
Explain why an electron microscope can show structures a light microscope cannot.
Model answer
Its higher resolving power lets two very close points be seen separately, so cells are shown in much finer detail.
- 6
How has the development of microscopes changed what biologists know about cells?
Model answer
Better instruments have revealed more sub-cellular structures, so their functions could be worked out.
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 Cell Biology, 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.