Explore the skills · QCAA
Biology
QCAA External Exam Revision · Units 3 & 4
Explore the subject and its skills. Full lessons, examples and practice require subject access. Accounts and purchasing are not open yet.
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Biodiversity and populations
- Genetic, species and ecosystem diversityRevision skill
- Biological species concept and its limitationsRevision skill
- Linnaean classification and scientific namingRevision skill
- Dichotomous keysRevision skill
- Lincoln index population estimatesRevision skill
- Species diversity measuresRevision skill
- Ecological sampling design and biasRevision skill
- Quadrats, transects and capture–recaptureRevision skill
- Biotic and abiotic factors affecting distribution and abundanceRevision skill
- Habitats, microhabitats and species distributionRevision skill
- Interpreting abiotic-factor ecological dataRevision skill
- Specht and Holdridge ecosystem classificationRevision skill
- Exponential and logistic population growthRevision skill
- r-selected and K-selected reproductive strategiesRevision skill
- Population growth rate and population changeRevision skill
Functioning ecosystems and succession
- Energy flow and transformation in ecosystemsRevision skill
- Ecological efficiency and productivity calculationsRevision skill
- Food chains, food webs and ecological pyramidsRevision skill
- Water, carbon and nitrogen cyclesRevision skill
- Predation, competition and symbiotic interactionsRevision skill
- Ecological niches and competitive exclusionRevision skill
- Keystone species and community structureRevision skill
- Analysing interactions and species removal from ecological dataRevision skill
- Human impacts on community structure and ecosystem functionRevision skill
- Changes to ecosystem carrying capacityRevision skill
- Primary and secondary ecological successionRevision skill
- Pioneer species and colonisationRevision skill
- Explaining successional changeRevision skill
- Comparing ecosystems across space and timeRevision skill
Genetics and heredity
- DNA, genes and chromosome structureRevision skill
- Prokaryotic and eukaryotic genetic materialRevision skill
- DNA replicationRevision skill
- Point and frameshift mutationsRevision skill
- Meiosis and genetic variationRevision skill
- Spermatogenesis and oogenesisRevision skill
- Chromosomal mutations and aneuploidyRevision skill
- Interpreting human karyotypesRevision skill
- Transcription and RNA processingRevision skill
- Translation and the genetic codeRevision skill
- Predicting mutation effects on polypeptidesRevision skill
- Gene expression and epigenetic regulationRevision skill
- HOX genes and regulation of morphologyRevision skill
- Inheritance patternsRevision skill
- Pedigrees and Punnett-square predictionsRevision skill
- Polygenic inheritance dataRevision skill
- Making recombinant DNARevision skill
- PCR and gel electrophoresisRevision skill
- Interpreting DNA profilesRevision skill
Continuity of life on Earth
- Microevolution and macroevolutionRevision skill
- Mutation, gene flow and genetic driftRevision skill
- Natural selectionRevision skill
- Stabilising, directional and disruptive selectionRevision skill
- Allele-frequency calculationsRevision skill
- Analysing selection-pressure dataRevision skill
- Divergent, convergent, parallel and coevolutionRevision skill
- Isolation, gene flow and speciationRevision skill
- Genetic diversity and extinction riskRevision skill
- Comparative genomics and dating divergenceRevision skill
- Inferring relatedness from cladograms, phylograms and sequencesRevision skill
- Evolutionary radiation and mass extinctionRevision skill