Biology Tools

Generate Punnett squares for monohybrid, dihybrid, incomplete dominance, and sex-linked crosses. Color-coded SVG grid with genotype and phenotype ratios and step-by-step analysis.

Simulate exponential, logistic, and Lotka-Volterra predator-prey population models. Interactive JSXGraph plots with carrying capacity, inflection points, phase portraits, and ecological presets.

Transcribe DNA to mRNA and translate codons into amino acid chains. Beautiful sequence diagram with color-coded nucleotides, codon brackets, amino acid pills, full 64-codon table, and reverse translation.

Calculate allele and genotype frequencies, test populations for HW equilibrium with chi-square, and simulate evolutionary forces like selection, drift, mutation, and migration over generations.

Explore Michaelis-Menten enzyme kinetics with interactive plots. Adjust Vmax, Km, substrate concentration, and add competitive, uncompetitive, or noncompetitive inhibitors. View Lineweaver-Burk double-reciprocal plots and temperature/pH activity curves.

Interactive viewer for cell division. Step through every phase of mitosis and meiosis with SVG chromosome visualizations. Track chromosome number (2n vs n), see crossing over and independent assortment in meiosis, and compare both division types side by side. Presets for human (2n=46), fruit fly (2n=8), onion (2n=16), and simple (2n=4) cells.

Explore photosynthesis rates under different light intensities, CO2 concentrations, and temperatures. See light response curves, compensation and saturation points, absorption vs action spectra, and the law of limiting factors.

Explore glycolysis, Krebs cycle, and electron transport chain. Compare aerobic vs anaerobic respiration, calculate ATP yields for glucose, fat, and protein substrates, and see how temperature affects metabolic rate.

Explore MacArthur-Wilson island biogeography, species-area relationships, habitat fragmentation, and diversity indices. Calculate Simpson's D and Shannon-Wiener H' from species count data.

Explore signal transduction cascades, dose-response curves, and feedback loops. Visualize receptor binding, kinase cascade amplification, Hill equation pharmacology, and positive/negative feedback in an interactive diagram.

Align DNA sequences with Needleman-Wunsch and Smith-Waterman algorithms. Translate codons, introduce mutations, compute Jukes-Cantor distances, and build UPGMA phylogenetic trees.

Explore stomatal conductance, transpiration rates, and water potential. Adjust leaf area, stomatal density, humidity, wind, and temperature to simulate potometer experiments and cohesion-tension water transport.

Simulate lac and trp operon regulation, eukaryotic gene expression, and signal-to-expression cascades. Toggle inducers, repressors, and enhancers to see how transcription rates and protein levels respond.

Explore circular plasmid maps with restriction enzyme sites, selectable markers, and gene inserts. Calculate transformation efficiency and visualize fragment sizes from restriction digests.

Digest DNA sequences with restriction enzymes and visualize fragments on a virtual gel. Select from 10 enzymes, perform single or double digests, and estimate fragment sizes from band migration.

Simulate animal behavior in choice chambers. Test phototaxis, hygrotaxis, thermotaxis, and chemotaxis for Drosophila, pillbugs, planaria, and C. elegans with chi-square statistical analysis.

Build energy pyramids and explore the 10% rule of ecological efficiency. Adjust transfer rates across trophic levels, compare energy, biomass, and number pyramids for different ecosystems.

Explore how directional, stabilizing, and disruptive selection reshape trait distributions over generations. Adjust heritability and selection strength to verify the breeder's equation R = h²S.

Watch a bee pollinate flowers and seeds travel the world. Match plants to their dispersal method, then design your own seed with wings, hooks, or floats to see how far it can go.

Set light, water, soil, and temperature conditions to grow virtual bean, sunflower, or grass plants. Compare two plants side by side. Learn what plants need with an interactive checklist

Match 18 animals to 6 habitats (desert, ocean, forest, arctic, grassland, wetland). Explore each animal's adaptations and discover what happens when habitats change

Build food chains and food webs by connecting producers, consumers, and decomposers. See energy flow arrows, auto-classify organisms by role, and simulate what happens when a species is removed

Explore life cycles of butterflies, frogs, flowering plants, and dogs with animated cycle wheels, drag-to-order practice, and side-by-side comparison mode

Interactive ecosystem model showing matter flow between sun, plants, animals, and decomposers. Build food webs, explore organism roles, and simulate what happens when species disappear.

Explore how traits are passed from parents to offspring. Sort traits as inherited or learned, predict offspring features, and discover how the environment can influence appearance.

Tap body parts to learn what they do. Explore how roots absorb water, how eyes detect light, and how fur keeps animals warm. Then design an organism for a challenging habitat.

Follow a signal from your eyes to your brain and back to your muscles. Match senses to sense organs, trace stimulus-response pathways, and compare human senses to incredible animal abilities.

Discover why wolves hunt in packs, penguins huddle in blizzards, and fish school together. Match group behaviors to survival benefits and explore what happens when animals lose their group.

Rescue displaced animals by matching them to their correct habitat and providing food, water, shelter, and space. Discover what every living thing needs to survive. Grades 2-5.

Discover what plants and animals need to survive. Match food, water, shelter, air, sunlight, and space to different living things. Grades K-1.

Match parent animals to their babies, learn baby animal names like puppy, foal, and calf, and discover inherited traits. Grades K-1.

Solve human design problems by copying animal and plant parts. Discover how beaver teeth, gecko feet, and lotus leaves inspire real-world tools. Grades K-1.

Clickable diagram of all 10 human body systems. Tap any system to discover its key organs, function, and a surprising fact — from the circulatory system to the endocrine and immune systems.

Click a food item and follow it through 6 digestive organs (mouth, esophagus, stomach, small intestine, large intestine, elimination). Each stage shows transit time, active enzymes, and how much of each nutrient is absorbed. A nutrient tracker bar chart shows carbs, protein, fat, fiber, and water remaining at each stage. Eight food items including apple, egg, steak, and milk.

Model how the immune system fights four pathogens (influenza, strep, common cold, E. coli) over a 21-day timeline. Compare vaccinated vs unvaccinated outcomes. View innate response (neutrophils/macrophages), B-cell antibody production, and T-cell activation on a multi-line SVG chart. Includes phase timeline, severity score, and estimated clearance day.

Select donor and recipient ABO/Rh blood types to see transfusion compatibility with a full 8x8 compatibility matrix colored green, yellow (emergency-only), and red. SVG antigen diagram shows A, B, and Rh antigens on red blood cells with matching antibody Y-shapes. Genetics mode shows a 4x4 Punnett square for ABO inheritance with phenotype probability summary.

Click any plant part (roots, stem, leaves, flower, fruit) on an SVG diagram to explore its function, key structures, fun fact, and evolutionary adaptations. Toggle a cross-section view showing xylem and phloem in stem and root. An animated canvas visualization shows blue water molecules moving up through xylem and amber sugar molecules moving through phloem.

Hardy-Weinberg with selection, mutation, drift, and migration acting on a single locus over generations. Track allele frequency p over time. Adjust population size N (with infinite N toggle to disable drift), three genotype fitnesses, forward and backward mutation rates, and migration rate plus source allele frequency. Run 10 stochastic replicates to see drift variance. de Finetti diagram shows the genotype trajectory through the simplex.