Amoeba (Amoeba proteus)
0.5 mm
Cell length while moving
A single cell that moves by pushing out pseudopods; big enough to see by eye. About 0.5 mm long when moving.
Published
How big is that?
0.5 mm is 7.1 times the width of a human hair and 7% of a grain of rice.
Amoeba is the 15th smallest of the 32 Tiny Worlds objects, and the 15th smallest of the 172 objects across all five SizeItUp games.
Closest in size from the other games: Black peppercorn (Kitchen Table), 4.865 mm across.
Size comparison
To scale, smallest to largest: Amoeba in orange beside the Tiny Worlds objects nearest in size, in teal.
| Object | Size | vs Amoeba |
|---|---|---|
| Grain of sand (Medium)A grain of medium sand, as geologists grade it. | 0.375 mm across | 75% of the size |
| Spider mite (Two-spotted, female)A sap-sucking mite that spins fine webs on houseplants, seen from above. | 0.4 mm long | 80% of the size |
| Amoeba (Amoeba proteus) | 0.5 mm long | – |
| Nematode worm (C. elegans)Caenorhabditis elegans, the tiny worm behind several Nobel prizes. | 1 mm long | 2× bigger |
| Poppy seedA kidney-shaped seed from the opium poppy, the kind on bagels. | 1.01 mm long | 2× bigger |
In other units
| Micrometres | 500 |
|---|---|
| Millimetres | 0.5 |
| Centimetres | 0.05 |
| Metres | 0.0005 |
How it's measured
Cell length while moving. Marshall et al. 2012, BMC Biology.
Sources
- doi.org: BMC Biology 10:101: roughly 500 μm in length when actively moving.
Checked against the source on .
Could you have guessed it by eye?
Amoeba is one of the objects in Tiny Worlds, a daily size comparison game: you stretch a shape to the size you think is right beside one you know.