Bacteria Classifying and Ordering Help
Introduction to Classifying and Ordering
This section looks at the different types of bacteria in much more detail.
Besides ancient bacteria, there are plants, fungi, and animals. Such defining and classifying of different groups of organisms is the essential work of taxonomy (tacks- ON -oh-me). Taxonomy looks for general rules or “laws” ( nom ) for the “arrangement” or “ordering” ( tax ) of organisms into groups of various sizes. As such, it is an essential feature of Natural History.
The Five-kingdom System Of Classification
Ever since Aristotle and other early naturalists began observing and collecting observations about organisms, just how to classify them into particular groups for convenient study has been a major issue. Taxonomy involves no set laws or rules of Nature. Rather, it is a human-constructed way of assigning organisms to particular groups, using highly orderly and systematic methods.
Because it is human-made, there is no single rock-solid way of classifying organisms. Instead, there are a number of different ordering systems or kingdoms commonly used by taxonomists (tacks- ON -oh-mists). Perhaps the most simple of these methods is the Five-Kingdom System. As Figure 6.1 clearly illustrates, the Five-Kingdom System consists of three kingdoms of multicellular (many-celled) organisms, plus two kingdoms of unicellular (single-celled) creatures. According to this system, most multicellular creatures belong to either the Kingdom Plantae ( PLAN -tie), Kingdom Fungi, or Kingdom Animalia (an-ih- MAIL -ee-uh). Obviously, these are the kingdoms of plants, fungi, and animals. And all single-celled organisms belong to either the Kingdom Protista (proh- TIS -tah) or Kingdom Monera (muh- NIR -uh).
Unicellular Kingdom Classifications
Kingdom Protista consists of the protists ( PROH -tists). Protists are often considered the “very first” ( protist ), that is, the most ancient, of all types of organisms. They are also among the simplest. The protists are eukaryotes, having a nucleus, but they are generally simpler than most plants, fungi, and animals. For example, the protist kingdom includes the amoebas (uh- ME -buhs). An amoeba is a single-celled eukaryote (Figure 6.1 below) that frequently “changes” ( amoeb ) the shape of its body as it moves through its environment.
Kingdom Monera is the one that includes the bacteria and all other types of prokaryotes. Since they lack a nucleus, all of the organisms within this kingdom have cells with cytoplasm that essentially stands “alone” (moner). The bacteria and other monerans (muh- NIR -uns) also lack other membrane-enclosed organelles, such as mitochondria and Golgi bodies. Monerans thus have only the most basic facets of cell anatomy and physiology.
Despite small cell size and structural simplicity, however, the Kingdom Monera and its vast populations of prokaryotes (such as bacteria) make up the majority of the Earth’s biomass or “living weight.” All of the bacteria on this planet, added together, weigh far more than all the elephants and whales and human beings combined!