Protists are single-celled organisms that live in water.

Protozoans are single-celled organisms.

Single-celled organisms have the most basic form in the biological world.

What is this organism?

I saw many animals at the zoo.

We took a walk in the primeval forest over the weekend.

There are only inanimate objects in this room.

The use of bioweapons is prohibited by international law.

The study of nekton is an important part of marine biology.

I love biology.