Osmosis and Cell Tonicity
Adjust solute concentrations inside and outside a cell and watch water move across the membrane until the cell swells, shrinks or bursts.
~15 min
10 topics · 10 live
Biology
Explore the machinery of life. Watch water cross cell membranes, take apart a cell, tune photosynthesis, turn glucose into ATP, unzip DNA, watch cells divide by mitosis and meiosis, predict offspring with Punnett squares, trace energy and nutrients through an ecosystem and see natural selection reshape a population.
Topics in Biology
Cell Structure and Organelles
Rotate and zoom an interactive 3D cell and click each organelle to learn what it does.
~12 min
Photosynthesis and the Light Reactions
Explore a leaf and a chloroplast, step through the light-dependent reactions and the Calvin cycle, and see how light, CO₂, water and temperature limit the rate.
~25 min
DNA Replication
Step through helicase, primase and DNA polymerase as a double helix copies itself.
~15 min
Natural Selection and Evolution
Change the environment and watch traits in a population shift across generations.
~15 min
Cellular Respiration and ATP Production
Watch glucose become ATP in the cytoplasm and mitochondria, step through glycolysis, the Krebs cycle and the electron transport chain, and see what happens when oxygen runs out.
~15 min
Mitosis and the Cell Cycle
Follow an animal cell through interphase and every stage of mitosis to two identical daughter cells, click its chromosomes and spindle, and compare mitosis with meiosis.
~15 min
Meiosis and Genetic Variation
Watch homologous chromosomes pair, cross over and separate through meiosis I and II, then flip their arrangement and make gametes to see how variation arises.
~15 min
Mendelian Genetics and Inheritance
Choose parent genotypes, build Punnett squares for one or two traits, and breed pea plants to compare predicted ratios with real chance.
~15 min
Ecosystem Energy Flow and Nutrient Cycling
Follow energy from the Sun through a meadow food web as it is lost as heat, watch decomposers recycle nutrients, and explore the carbon and nitrogen cycles.
~15 min