With few exceptions, can only be seen with the help of a microscope
Live on, in, and around most living and nonliving things
Some examples include: earthworms, starfish, amoebas, spiders, and snails
Does not possess green coloration
A living thing other than a plant or animal
An animal that does not have a backbone
Single-celled organisms
Must live in or on plants, animals, or decaying material
