Classification of living creatures

Scientists have classified all living creatures into large groups. Previously only two groups were known: animals and plants. New groups were added, as humans were able to observe even very small organisms by microscopes. So you can differentiates six groups or socalled „kingdoms“:

Bacteria

Organism type: unicellular bacteria

Distribution: worldwide

Bacteria can stand (and live under) all environmental circumstances. For example, you can count the cyanobacteria, which once gave the first oxygen into the atmosphere of the earth, to this group. However, there are also pathogenic organisms such as cholera or typhus. In addition useful bacteria, which clear the sewerage or turn milk into yogurt, belong to that group, too.

Archaea:

Organism type: unicellular bacteria

Distribution: extreme habitats

The archaea belong probably to the oldest creatures on the earth. They also survive in extremely hostile habitats, for example in radioactive waste, very hot water, lye or acid.

Protista

Organism type: mycetozoan (slime mold), algae, protozoa

Distribution: salt water and fresh water (prevalent), mainland (in particular)

In this kingdom, different, not closely related organisms are combined. They are neither bacteria nor archaea, fungi, plants or animals. They are unicellular organisms – but with a nucleus. They produce some of their nutrients by themselves. They partly live from other organisms.

Fungi

Organism type: molds, yeasts

Distribution: worldwide

For a long time, fungi were regarded as plants until researchers noticed that they did not produce their own nutrients. Instead, they get their energy from the degradation of the remains of dead plants or animals. There are multi-cellular and unicellular fungi. They are genetically and chemically closer to animals than to plants.

Plants:

Organism type: green algae, mosses, conifer, flowering plants

Distribution: worldwide, Polar Regions (in particular)

Plants are multi-cellular, complex organisms that produce their nutrients by themselves. This kingdom includes huge trees as well as tiny mosses. They are existing in most habitats, including the oceans. Plants produce the oxygen we need to breathe and live.

Animals

Organism type: insects, fish, mammals, crustaceans, reptiles, amphibians

Distribution: worldwide

This kingdom includes simply developed animals, which have neither a spinal cord nor a brain (like sponges), up to complex mammals like us humans. Animals cannot produce their own nutrients and must therefore eat other living organisms in order to survive.