Rational Expressions Short Course. 1  Definitions covers the definition of a rational expression including what it means for a rational expression to be undefined and simplified.  Arithmetic reviews addition, subtraction, multiplication and division of rational expressions.
Taxonomic Hierarchy Categories were also introduced by Linnaeus. They are also known as Linnaean hierarchy. It is defined as sequence of categories in a decreasing or increasing order from kingdom to species and vice versa. Kingdom is the highest rank followed by division, class, order, family, genus and species.Species is the lowest rank in the Hierarchy.The hierarchy has two categories which are obligate and intermediate.Obligate means they are followed strictly and range from kingdom to species as said above.pecies is the lowest rank in the Hierarchy. The hierarchy has two categories which are obligate and intermediate. Obligate means they are followed strictly and range from kingdom to species as said above.
In biological classification, rank is the relative level of a group of organisms (a taxon) in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, order, class, phylum, kingdom, domain, etc. A given rank subsumes under it less general categories, that is, more specific descriptions of life forms.