Protozoa are single-celled organisms that act a lot like animals in that they move around and feed on prey
Bacteria are tiny little organisms that are everywhere around us. We can't see them without a microscope because they are so small, but they are in the air, on our skin, in our bodies, in the ground, and all throughout nature. Bacteria are single-celled microorganisms.
Viruses are microscopic parasites, generally much smaller than bacteria. They lack the capacity to thrive and reproduce outside of a host body.
Fungi are a group of living organisms which are classified in their own kingdom. This means they are not animals, plants, or bacteria. Fungi are found throughout the Earth including on land, in the water, in the air, and even in plants and animals.
Algae are organisms, or living things, that are found all over the world. Algae are very important because they make much of Earth's oxygen, which humans and other animals need to breathe. Some algae, such as seaweed, look like plants. However, algae are actually neither plants nor animals
The four major types of germs are bacteria, viruses, fungi, and protozoa. They can invade plants, animals, and people, and sometimes they can make us sick. Bacteria (say: BAK-teer-ee-uh) are tiny, one-celled creatures that get nutrients from their environments in order to live.