Could you survive as one cell?

Part 1 of 4 · Life on your own

You are a paramecium

You live in a pond. Every job a body does, you do with one cell: swim with your hairs (cilia), swallow bacteria into a little food bubble, squirt out waste, and pump out the pond water that keeps leaking in. Your insides are saltier than the pond, so water flows in all the time. You saw why in the raisin lesson.

Goal: stay alive for 45 seconds. Tap or click where you want to swim, or use the arrow keys.

Part 2 of 4 · Life in a team

Now you are a muscle cell

You're one cell in an arm muscle. You have the same four needs as the paramecium, but look: you have no pump button and no waste button. Other cells, specialized for other jobs, look after your meters for you. Your one job is to contract when a nerve tells you to.

Try: press Contract each time the nerve flashes. Then switch off one of your helpers, or take yourself out into the pond.

In the picture: a tiny blood vessel with red blood cells along the top, you (a long muscle cell) in the middle, the nerve that tells you when to contract on the right, and a white blood cell on patrol at the bottom.

Your helpers (tap to switch one off)

Part 3 of 4 · Same jobs, different workers

Who does each job?

Both of you had the same jobs to get done. In the paramecium, each job is done by a part of the one cell. In your body, each job is done by a whole team of specialized cells.

Try: tap a worker below, then tap the empty box it belongs in.

Part 4 of 4 · Size can fool you

One cell or many?

You can't always tell by size. Decide for each living thing.

Putting it back together

The deal you make by being many cells

A body is not a pile of cells. It is a team where each cell has given up doing everything so it can do one thing very well. Next question: how do those specialized cells get organized into hearts, stomachs and lungs?