They breathe through their skin. Air dissolves on the mucus of their skin, so they MUST stay moist to breathe. If worms dry out, they suffocate. As fresh air is taken in through the skin, oxygen is drawn into the worm's circulatory system, and the worm's hearts pump the oxygenated blood to the head area.
Humans are called heterotrophs
Carbon dioxide and oxygen are two molecules that undergo this simple diffusion through the membrane.
1.
Paramecium
2.
Amoeba
3.
Paramecium
4.
Euglena
5.
Volvox
6.
Amoeba?
7.
Amoeba
8.
Cilia
9.
Flagellum
10. Psuedopods
11. Flagella
12. Euglena
(Chloroplast)
13. Amoeba
14. Euglena
15. Paramecium
16. Paramecium
17. Amoeba
18. Volvox
I hope this is all correct!
