Cell explorer: plant, animal, bacterium sim
Turn a 3D plant, animal or bacterial cell under the microscope, switch between light and electron microscope views, and fill a table of which structures each cell has and which only an electron microscope can show.
Cells · covers the O-Level, IGCSE, GCSE topic
What the sim shows
A compound light microscope (LM) on the bench, with three prepared slides: a pondweed leaf (plant cells, unstained), cheek cells stained with methylene blue (animal cells), and rod-shaped bacteria stained with crystal violet. The round close-up is a 3D model of one cell at its real size, with a scale bar. Drag it to turn it. The switch swaps the close-up between what a light microscope can resolve (about 200 nm, from d = λ ÷ 2NA = 550 nm ÷ 2.8) and what an electron microscope (EM) can resolve (about 0.1–1 nm; the model uses 0.5 nm). A structure is shown clearly when it is at least 5 times the resolution, faintly when it is 1–5 times, and not at all when it is smaller. Boundaries (membranes, the cell wall) show as edges whenever the thing they surround is resolved. In plant cells the membrane is pressed against the wall and is not seen separately; in bacteria the wall and membrane are seen together as the edge. Chloroplasts lie in the thin cytoplasm against the wall, above and below the vacuole, not inside it. Blur in the light view is a Gaussian of σ ≈ 0.36 × resolution. Idealised: the 3D cell stands for what each microscope can resolve. A real LM shows a flat, focused slice; a real EM is a separate, room-sized instrument that needs a thin section, fixed and stained with heavy metals, and gives black-and-white images; the EM view here is coloured to tell the structures apart, as false-colour micrographs are. Ribosomes and nuclear pores are drawn at least about 1 px across so they show.
- The LM / EM switch: light microscope (about 200 nm) or electron microscope (about 0.5 nm)
- The close-up: a 3D model of one cell at real size, with a scale bar
- Tap a structure, or a chip, to name it or hide it
Use it in your lessons
- Try it here: anyone can unlock 2 figures free, and a free account unlocks up to 5. Runs on a laptop, a Chromebook or a phone; nothing to install.
- Present it and share student links with the teacher plan, from US$5 a month, billed yearly.
- Put it on your own website or LMS for US$9, paid once, or every sim from US$29 a month.
Free guide: 12 practicals as sims, and how to run one in a lesson →
Need a version for your exact set-up? Have one made: US$49 a figure in an order of 5.
More biology sims
- Exercise and heart rate: take the pulse simSet the exercise with a metronome on a step, count the pulse for 15 s at the wrist, record resting, straight-after and recovery readings in an empty table, plot them with a best-fit curve, and plan a fair test.
- Inspired and expired air simBreathe in through one tube of limewater and out through the other, watch the cross behind each tube, and find out why only the air you breathe out turns limewater milky.
- Liver and hepatic portal vein simPlay a meal or a fast half an hour at a time, sample the hepatic portal vein and the hepatic vein, and see the liver store glucose as glycogen, release it again, and turn excess amino acids into urea.
- Molecule builder simDrag glucose units into starch, glycogen or cellulose, amino acids into a polypeptide, or glycerol and fatty acids into a fat, count the water each join releases, and split the bonds again by hydrolysis.
- Mystery food bench simRun the iodine, Benedict's, biuret and ethanol emulsion tests on an unknown food, heating the Benedict's tube in a water bath, record each colour in a results table and work out which food it was.
- Peristalsis simContract the circular muscles behind a bolus and the longitudinal muscles in front of it, segment by segment, then turn the oesophagus upright, lying down or upside down and switch gravity off: the food still arrives at the same speed.