Cavalier-Smith's system of classification scheme they reintroduced the classification with the division of prokaryotes superkingdom into two kingdoms, Bacteria (=Eubacteria) and Archaea (=Archaebacteria). This is based on the consensus in the Taxonomic Outline of Bacteria and Archaea (TOBA) and the Catalogue of Life. Cavalier-Smith's system of classification The classification system of life introduced by British zoologist Thomas Cavalier-Smith involves systematic arrangements of all life forms on earth. Following and improving the classification systems introduced by Carl Linnaeus, Ernst Haeckel, Robert Whittaker, and Carl Woese, Cavalier-Smith's classification attempts to incorporate the latest developments in taxonomy. His classification has been a major foundation in modern taxonomy,
Structure (category theory) the morphisms are group homomorphisms: that is, of structures on one type, and mappings respecting that structure. Starting with a category "C" given abstractly, the challenge is to infer what structure it is on the objects that the morphisms 'preserve'. The term "structure" was much used in connection with the Bourbaki group's approach. There is even a definition. Structure must definitely include topological space as well as the standard abstract algebra notions. Structure in this sense is probably commensurate with the idea of concrete category that can be presented in a definite way — the topological case means that infinitary