Pseudopod (pseudopodium)A temporary arm of cytoplasm. The amoeba pushes pseudopodia out to creep along and to flow round its food, then draws them back in.
Plasma membrane (cell membrane)The thin, flexible membrane that encloses the whole cell. A pseudopod forms where the cytoplasm pushes it outward, and food is taken in through it at any point.
EctoplasmThe clear outer layer of the cytoplasm, just under the membrane. It is firmer than the endoplasm and has no granules in it.
Inside the cell 4
NucleusHolds most of the cell's DNA. A single round body suspended in the endoplasm. It has no fixed place: it shifts as the amoeba moves.
Contractile vacuoleA clear bubble that the cytoplasm's water slowly fills. Then it suddenly empties the water out of the cell. It keeps a freshwater amoeba from taking in too much water.
Food vacuoleA bubble formed round food the amoeba has engulfed. The food is digested inside it, which is why an old textbook calls it a sort of temporary stomach.
EndoplasmThe granular inner part of the cytoplasm. The nucleus, the food vacuoles and the contractile vacuole all lie in it.
How this list was compiled: Every name was checked on 2026-09-30 in two places, for facts only and with nothing copied. (1) R. W. Hegner, An Introduction to Zoology (1910), the chapter on Ameba, https://archive.org/details/introductiontozo00hegnrich, and the same author's College Zoology (1912), https://archive.org/details/collegezoology00hegn; both are in the public domain. (2) Wikipedia, text only: Amoeba (genus), Amoeba proteus, Pseudopodia, Ectoplasm (cell biology), Endoplasm and Contractile vacuole, for example https://en.wikipedia.org/wiki/Amoeba_(genus). (3) For the plasma membrane, which the 1910 book does not name: two journal abstracts on Amoeba proteus read through Europe PMC, https://europepmc.org/article/MED/11129797 and https://europepmc.org/article/MED/17602276. Licence: own work
The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work
How it works
This worksheet is an unlabeled diagram of the amoeba as it looks under a microscope: one cell with five blunt arms, three kinds of round body inside and a small alga drifting beside it. Seven label lines take a name.
Read the full guide
Word bank for the unlabeled amoeba diagram
Pseudopod, plasma membrane, ectoplasm, endoplasm, nucleus, contractile vacuole, food vacuole: one for each label line. One line points at a single arm and one at a single bubble with food in it, but all five arms are pseudopods and the sheet shows three food vacuoles. A class may say pseudopodium, cell membrane, ectosarc or endosarc instead.
Three questions to set with the worksheet
Which part gets rid of extra water? (The contractile vacuole.) Which layer holds the granules, the nucleus and the food vacuoles? (The endoplasm.) What is the amoeba about to do to the alga beside it? (Flow round it with its pseudopods and take it into a food vacuole.)
The alga with the tail is not part of the amoeba. It is food about to be taken in, and it takes no label.
On paper the diagram is black and white: the three layers show as an outline, a clear band and a dotted middle.
Questions and answers
Where is the pseudopod located in an amoeba?
It has no fixed place. A pseudopod is a temporary arm that the cell pushes out in the direction it is moving and later draws back in, and an amoeba can put out several at once. On the worksheet all five arms are pseudopods.
What does an amoeba look like under a microscope?
A colorless cell that keeps changing shape as arms push out and draw back. The rim is clear and the middle is grainy, and in the middle sit a nucleus, a clear contractile vacuole and food vacuoles.
Where do amoebas live?
The amoeba studied in classrooms, Amoeba proteus, lives in fresh water such as ponds and streams. It feeds there on algae and other small organisms.
Is an amoeba one cell?
Yes. The whole organism is a single cell with a nucleus, so one cell does everything: it moves, takes in food and pumps out extra water.