Study guides
Biology study guides
Plain-language biology guides for high school and AP Biology students. Each one explains the idea, works through real examples like Punnett crosses and codon charts, lists the mistakes teachers see most, and ends with practice questions. Facts are checked against OpenStax Biology 2e, and every computable answer was recomputed in code.
Updated
- 1Cell organelles and their functionsCell organelles and what they do: nucleus, ribosomes, ER, Golgi, mitochondria, chloroplasts and more, plus plant vs animal vs bacteria cells and practice.
- 2EnzymesHow enzymes work: activation energy, the active site, induced fit, and how temperature, pH and inhibitors change enzyme activity. Data examples and practice.
- 3Cellular respirationCellular respiration step by step: glycolysis, the citric acid cycle and the electron transport chain, where each happens, fermentation and practice.
- 4PhotosynthesisPhotosynthesis explained step by step: the overall equation, light-dependent reactions, the Calvin cycle, where each happens, and worked counting examples.
- 5Mitosis vs meiosisMitosis vs meiosis compared: purpose, phases, chromosome numbers and genetic variation, with a side-by-side chart, counting examples and 5 practice questions.
- 6DNA replicationDNA replication step by step: helicase, primase, DNA polymerase and ligase, leading vs lagging strands, base pairing and semiconservative copying.
- 7Transcription and translationTranscription and translation step by step: DNA to mRNA to protein, reading codons, the codon chart and mutations. Worked examples and practice questions.
- 8How to do Punnett squaresHow to do Punnett squares: monohybrid, test cross, dihybrid 9:3:3:1 and sex-linked crosses, with genotype and phenotype ratios explained and practice.
- 9Natural selectionNatural selection explained: variation, inheritance, overproduction and survival, with antibiotic resistance, population data and Hardy-Weinberg practice.
- 10Food webs and energy pyramidsFood chains, food webs, trophic levels and energy pyramids explained, with the 10% rule, trophic level transfer efficiency calculations and practice questions.
- 11The immune system basicsImmune system basics: barriers, inflammation and phagocytes (innate), B cells, T cells and antibodies (adaptive), memory and vaccines, with a comparison table.
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