Biology
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Biology tools by topic
29 resources. Choose a topic to narrow the list.
Magnification & actual size
Convert between image size, actual size and magnification.
Scale bar actual size
Use a scale bar to find a specimen’s actual size.
Field-of-view density
Estimate number per area of a circular field of view.
Surface area : volume
Compare surface area and volume for simple shapes.
Mean, median, mode & range
Summarize a dataset with centre and spread.
SD & standard error
Find sample SD, population SD and standard error.
Error bar ranges
Find the limits around a mean and label the bar type.
Regression, r & R²
Fit a straight line to paired measurements.
Two-sample t-test
Compare independent or paired samples with a t-test.
Chi-squared test
Compare observed counts with expected counts.
Lincoln index
Estimate population size from capture and recapture.
Simpson reciprocal index
Calculate diversity from species counts.
Quadrat population estimate
Scale a mean quadrat count to the habitat area.
Energy transfer efficiency
Express transferred energy as a fraction of input energy.
Population growth
Find absolute, percentage and average population changes.
Hardy–Weinberg
Relate allele and genotype frequencies under equilibrium.
Allele frequency
Find allele frequencies from diploid genotype counts.
Recombination frequency
Find the proportion of recombinant offspring.
Rate of change
Find a signed average change per unit time.
Percentage change & difference
Calculate a percentage change or percentage difference.
Percentage uncertainty
Express an absolute uncertainty as a percentage.
Significant figures
Round a written number to significant figures.
Dilution
Solve the dilution relationship for one unknown.
Serial dilution
Track concentration through repeated dilution steps.
Calibration curve
Fit standards and infer an unknown from its response.
Paper 1B
Data-analysis and experimental-skills guide for IB Biology Paper 1B.
Experimental skills
Experimental skills, evaluation and data-quality guidance for Biology.
Paper 1B practice
Original Paper 1B-style data and experimental reasoning practice for Biology.
Past papers
Official specimen papers and past-paper access.