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 biotechnologyImpact of environmental change
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 reproductionContraceptionThe use of hormones to treat infertilityNegative feedbackPlant hormones and their uses
Infection and Response
Topic overviewCommunicable (infectious) diseasesViral diseasesBacterial diseasesFungal and protist diseasesHuman defence systemsVaccinationAntibiotics and painkillersDiscovery and development of drugsProducing monoclonal antibodiesUses of monoclonal antibodiesDetection and identification of plant diseasesPlant defence responses
Inheritance, Variation and Evolution
Topic overviewSexual and asexual reproductionMeiosisAdvantages and disadvantages of sexual and asexual reproductionDNA and the genomeDNA as a polymer of four nucleotidesProtein synthesis and complementary base pairingMutations, protein shape and non-coding DNAGenetic 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
Bioenergetics
Rate of photosynthesis
- 3 things to know
- Paper 1
Overview
How light intensity, carbon dioxide, temperature and chlorophyll affect the rate, calculating and graphing a rate from bubble counts, limiting factors on graphs, the inverse square law, greenhouse costs, the pondweed investigation with its controls, gas syringe and hazards, writing and testing a hypothesis, and rates from tangents.
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Describe the effect of increasing light intensity on the rate of photosynthesis.
Key term
Explain why raising the carbon dioxide concentration around a plant can increase its rate of photosynthesis.
Questions from this subtopic
Each one with the model answer underneath.
- 1
Describe the effect of increasing light intensity on the rate of photosynthesis.
Model answer
The rate increases as light intensity increases, then levels off at high intensities.
- 2
Explain why raising the carbon dioxide concentration around a plant can increase its rate of photosynthesis.
Model answer
Carbon dioxide is a raw material for photosynthesis, so supplying more of it lets the reaction go faster.
- 3
Explain why the rate of photosynthesis first rises and then falls as temperature is increased.
Model answer
It rises because the reacting molecules and enzymes have more energy, but above the optimum the enzymes are denatured so the rate falls.
- 4
How does the amount of chlorophyll in a leaf affect the rate of photosynthesis?
Model answer
Less chlorophyll means less light is absorbed, so the rate of photosynthesis is lower.
- 5
How is the rate of photosynthesis of a piece of pondweed calculated from a count of gas bubbles?
Model answer
Divide the number of bubbles produced by the time taken, giving a rate in bubbles per minute.
- 6
A piece of pondweed releases 90 bubbles in 3 minutes. Calculate the rate of photosynthesis in bubbles per minute.
Model answer
30 bubbles per minute.
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 Bioenergetics, 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.