What it does
Every living thing is made of cells, and each cell is full of smaller parts called organelles, each with its own job. This explorer draws three cells you meet at school:
- a plant cell, with its cell wall, large vacuole and green chloroplasts;
- an animal cell, with no wall, small vacuoles and lysosomes;
- a bacterium, a much smaller cell with no nucleus: its DNA lies loose in the cytoplasm.
Tap any part to see its name, what it does and which cells have it. Zoom in on it brings that part up close. The compare table puts the three cells side by side, and How much bigger? shows how much the drawing is magnified on your own screen. It fits Class 9 Science: the fundamental unit of life (cell membrane, cell wall, nucleus, cytoplasm, organelles, prokaryotes and eukaryotes) and Class 11 Biology: cell, the unit of life, which adds the nucleolus, centrioles, plasmodesmata and the parts of a bacterium. Next, see water move in and out of cells in the osmosis lab, what chloroplasts do in the photosynthesis lab, and read a DNA sequence with DNA sequence tools.
How to use it
- Pick the level. Class 9 shows the main parts with a one-line job each. Class 11 adds more parts and a longer explanation of each.
- Pick a cell: plant, animal or bacterium.
- Tap a part. It lights up and the box below tells you about it. On a computer you can also move with the Tab key and press Enter.
- Zoom in on it to look closer; press again to zoom out. The scale bar changes as you zoom.
- Compare the cells. Tap a row to jump to that part in the drawing. Download the table as a CSV file, or the drawing and table as an image, PDF or Word file.
- How much bigger? Shows the magnification of the drawing on your screen and works out the total magnification of a light microscope from its two lenses.
- Check yourself: fresh questions each time, with the working shown.
Worked example
A typical plant cell in this explorer is 50 µm (0.05 mm) across. If the drawing on your screen is 90 mm wide, the magnification is 90 mm ÷ 0.05 mm = ×1800. Under a light microscope with a ×10 eyepiece and a ×40 objective, the total magnification is 10 × 40 = ×400, so the same cell looks 0.05 × 400 = 20 mm across. A bacterium only 2 µm long would look 0.8 mm across at ×400, which is why bacteria need about ×1000 to be seen clearly.
Plant, animal and bacterial cells in one line each
- Plant cells have a cellulose wall, one large vacuole and chloroplasts, as well as everything an animal cell has (except, usually, centrioles and lysosomes).
- Animal cells have no wall, so their shape is more rounded or irregular, and they burst in plain water.
- Bacteria are prokaryotes: no nucleus and no membrane-bound organelles such as mitochondria; smaller 70S ribosomes; often a flagellum and plasmids.
FAQ
Why are the parts so spread out? To make them easy to tap. Real cells are packed with organelles, and the ER and ribosomes are everywhere.
Do plant cells have mitochondria? Yes. Plants respire all the time, day and night, so they need mitochondria as well as chloroplasts.
Why do the sizes say “about”? Cells vary a lot: some plant cells are 10 times bigger than others. The sizes here are round values for the sums.
Where the numbers come from
- Drawings and descriptions are fibub's own, written in plain English from standard cell biology. They are simple teaching drawings, not traced from any book.
- Typical cell sizes (plant 50 µm, animal 20 µm, bacterium 2 µm) are round teaching values; real cells vary a lot.
- Magnification = image size ÷ real size, and total magnification = eyepiece × objective, are standard formulas. Nothing you enter is stored or sent anywhere.
Standard scientific values, such as constants, atomic weights and melting points, are facts found in every textbook; we name where ours were checked. If you are an author or publisher and want a value, a credit or a table changed or removed, tell us and we will act quickly.
Last updated 2026-11-09.