What Are the Six Kingdoms of Life As They Are Now Identified?

Archaebacteria

• Archaebacteria, like eubacteria, fall within the larger category of prokaryotes. Prokaryotes are bacteria, the most basic and primitive type of single-celled organism. According to the Columbia University website, the ability to live in extreme conditions is a primary characteristic of archaebacteria. They can survive in extremely hot, acidic or salty water and do not require oxygen.

Eubacteria

• The chemical makeup of eubacteria separates them from archaebacteria, their closest relatives. Eubacteria are the most common type of bacteria and they exist almost everywhere. Most eubacteria are helpful. Some are capable of producing vitamins and foods such as yogurt. Other varieties, however, are harmful to humans, such as streptococci and E. coli.

Protista

• The protista kingdom is like a receptacle for biological leftovers. Any organism that does not fit within one of the other five kingdoms finds a home among the protistas. The kingdom consists primarily of advanced single-celled organisms, but also contains a number of simple multicellular organisms. Algae, protozoa and slime molds fall within the protista kingdom.

Fungi

• Fungi are multicellular organisms that, unlike plants, are incapable of photosynthesis. They produce food by breaking down the material of other dead or living organisms. The fungi kingdom includes molds, mushrooms and yeasts.

Plants

• The plant kingdom is the second largest of the six kingdoms. It contains all the world's flowering plants, trees, mosses and ferns. Plants are multicellular and produce their own food via photosynthesis.

Animals

• Animals are complex multicellular organisms that are capable of locomotive movement. Unlike plants, animals cannot photosynthesize. They must obtain all necessary energy and minerals by ingesting organic compounds. The animal kingdom contains a wide range of organisms. It includes simple sponges and corals, complex invertebrates like insects and crustaceans and complex vertebrates like reptiles and mammals. It is the largest of all the six kingdoms, with more than 1 million different species.