Key term
OCR GCSE Combined Science Biology J250
Cell Level Systems
Topic overviewMicroscopy, and sub-cellular structuresDNA structure: polymer, double helix and nucleotidesEnzyme action, and investigating enzymesCellular respiration as an exothermic processAerobic and anaerobic respiration comparedSynthesis and breakdown of carbohydrates, proteins and lipidsPhotosynthesis: producers and the processPhotosynthesis as endothermic, and investigating itLimiting factors in photosynthesis
Community Level Systems
Genes, Inheritance and Selection
Topic overviewGenetic terms, and the genomeGenome, environment and mutationsHaploid, diploid and meiosisSingle gene inheritance and Punnett squaresSex determination and characteristics controlled by many genesVariation within a population, and classificationNatural selection and evolutionEvidence for evolution from fossils and antibiotic resistance
Global Challenges
Topic overviewField investigations, and human impact on ecosystemsMaintaining biodiversity, monitoring conservation and ecotourismSelective breeding and genetic engineeringHealth, disease, and types of diseaseInteractions between diseases, and how they spreadReducing the spread of disease, and named examplesWhite blood cells, antibodies and plateletsNon-specific defences and the immune systemVaccines, medicines and aseptic techniqueDeveloping new medicines, and non-communicable diseaseTreating cardiovascular disease, and lifestyle factorsCancer, and the use of stem cells in medicineGene technology in medicine, and the human genome
Organism Level Systems
Topic overviewThe nervous system and coordinated responsesThe reflex arcHormonal coordination, thyroxine and adrenalineHormones in reproduction and the menstrual cycleContraception and treating infertilityHomeostasis and control systems in the bodyInsulin and glucagon in blood sugar controlType 1 and type 2 diabetes
Scaling Up
Topic overviewDiffusion, osmosis and active transportMitosis, the cell cycle and cell differentiationStem cells in animals and meristems in plantsSurface area to volume ratio and exchange surfacesThe circulatory system, the heart and blood vesselsRed blood cells and plasmaRoot hair cells, transpiration and translocationXylem and phloemFactors affecting water uptake, and the potometer
Community Level Systems
Levels of organisation, and abiotic and biotic factors
- 3 things to know
- Paper 8 (Biology)
Overview
The levels of organisation from individual organism to population, community and ecosystem, what a habitat is, the difference between abiotic and biotic factors, how temperature, light intensity, soil pH and moisture affect where plants grow and which species live in a habitat, and how predators and food shortage act on populations.
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Define population, community and ecosystem in that order, from the smallest level of organisation to the largest.
Key term
List the levels of organisation in an ecosystem, from the smallest to the largest.
Questions from this subtopic
Each one with the model answer underneath.
- 1
List the levels of organisation in an ecosystem, from the smallest to the largest.
Model answer
Individual organism, then population, then community, then the whole ecosystem.
- 2
What is a population?
Model answer
All the organisms of one species living in the same habitat at the same time.
- 3
What is a community?
Model answer
All the populations of the different species living together in one habitat.
- 4
What is an ecosystem?
Model answer
A community of organisms together with the non-living parts of their surroundings, interacting as one system.
- 5
What is a habitat?
Model answer
The place where an organism lives.
- 6
All the oak trees growing in one wood are an example of which level of organisation?
Model answer
A population.
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 Community Level Systems, 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.