Unicellular Organisms (Single-celled)

* Bacteria: E. coli, Salmonella, Lactobacillus, Cyanobacteria (blue-green algae)

* Protists: Amoeba, Paramecium, Euglena, Diatoms

* Yeast: Saccharomyces cerevisiae (baker's yeast)

* Archea: Halophiles (salt-loving), Thermophiles (heat-loving)

Multicellular Organisms (Many-celled)

* Animals: Humans, dogs, cats, birds, fish, insects, worms

* Plants: Trees, flowers, grasses, ferns, mosses

* Fungi: Mushrooms, molds, yeasts (some are unicellular, some are multicellular)

* Algae: Seaweed, kelp (some are unicellular, some are multicellular)

Note: Some organisms, like fungi and algae, can be both unicellular and multicellular depending on the species.