Order taxonomic

Until recently, the presence or absence of articulatory structures along the posterior margin of the valves of brachiopods was used as a primary character in the discrimination of two first order taxonomic units within the Phylum, generally recognised as being of Class rank (e.g. Huxley, 1869 Williams and Rowell, 1965). Stemming from... 

Except for the mouse tissue, in every other case the data showed that the accepted scheme for the metabolic organization and hormonal regulation of the young rat s fat cell had to be revised in one or more major respects. Certain novel features are shared by the fat cells of insects of different species other characteristics are exhibited by fat cells of different bird species and even within the rodent order, taxonomical-ly-correlated metabolic characteristics are emerging. 

The chapters in this book are arranged roughly in the chronological order of bioluminescence systems discovered, based on the date of the major breakthrough made in each bioluminescence system, such as the discovery of ATP in the firefly system (McElroy, 1947) and the identification of fatty aldehyde as the luciferin in luminous bacteria (Cormier and Strehler, 1953). This differs from Harvey s 1952 book, which is arranged in the order of taxonomic classification. 

As there exists such a distinct difference in the spectrum of the volatile diterpenic components of both species, it would be advantageous to transfer these results to TLC in order to display these taxonomic marker substances as a tool for quality assurance operations. 

The following section describes the isolation of these substances, which are qualihed as taxonomic markers, in order to compare their identity with the mentioned diterpenes of the GC. 

In the sections that follow, the various bug families are dealt with in their commonly accepted taxonomic order [3]. It should be noted that pheromones have been described from less than half of the bug families. Even for those families in which pheromones are known, pheromone identifications have been carried out for only a few species, leaving a vast number of semiochemicals still to be discovered. 

Abstract This chapter reviews chemical structures of biologically active, volatile compounds in beetles. Techniques used for structure elucidation are briefly discussed as well as facts and speculations on the biosynthesis of target compounds. Syntheses of selected substances are cursorily presented. The order of sections follows taxonomic classifications. Depending on the biological significance of relevant compounds in certain taxa, the corresponding sections are again subdivided into attractive compounds (mostly intraspecifically active pheromones) and defensive compounds (mostly interspecifically active allomones). 

DNA/DNA hybridization studies indicate a taxonomic revision for these three species is in order. Even though these species produce spores (unpublished results) they bear no genetic similarity to C. thermocellum. 

The use of enantiomers as additional markers for taxonomic characterization of aromatic plants may be very helpful. The differences in the enantiomeric distribution of trans- and cis- sabinene hydrates in two Origanum species enable the species to be distinguished in spite of their similar essential oil compositions. A further study on the natural variation of the enantiomeric composition within a wild population may be carried out in order to examine the stability in a taxon (including the possible presence of chemotypes). The enantiomeric ratio of essential oil components is a reliable parameter for assessing quality because it may be indicative of adulteration, contamination, aging, shelf life, technological process and the botanical source of a specific chiral compound. ... 

The organismic sources of the metabolites are reported in the charts at the lowest possible taxonomic level (species, genus, family, order, phylum), as required by the distribution of the metabolites at issue. With terrestrial plants the tradition of giving also the family was always followed, although a broader exploration of plants, and the advent of high-sensitivity analytical systems, have rendered the family of scarce taxonomic significance. With few exceptions of highly specific metabolites, the order is the taxonomic rank most representative of the distribution of natural products. 

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