АкушерствоАнатомияАнестезиологияВакцинопрофилактикаВалеологияВетеринарияГигиенаЗаболеванияИммунологияКардиологияНеврологияНефрологияОнкологияОториноларингологияОфтальмологияПаразитологияПедиатрияПервая помощьПсихиатрияПульмонологияРеанимацияРевматологияСтоматологияТерапияТоксикологияТравматологияУрологияФармакологияФармацевтикаФизиотерапияФтизиатрияХирургияЭндокринологияЭпидемиология

TAXONOMY

1. Taxonomy in broad sense is the science of classification, but more strictly the classification of living and extinct organisms, i.e., biological classification. The term is derived from the Greek taxis ("arrangement") and nomos ("law"). The taxonomist creates from a varied array of organisms a hierarchy of groupings, or taxa, that have an orderly relationship to each other. The basic unit in taxonomy is the species.

2. Most modern taxonomists attempt to group organisms so as to reflect evolutionary relationships. The basic method of taxonomy is to compare the characteristics of the structure of living and extinct organisms by the methods of comparative anatomy and to interpret their differences and similarities in the light of comparative genetics, biochemistry, physiology, embryology, behaviour, ecology, and geography.

3. Authorities once divided organisms into two simple categories, or taxa - the kingdoms Plantae and Animalia. A third kingdom, Protista, was later proposed for those organisms that are not clearly plant or animal, such as the protozoa, bacteria, and algae. Improvements in biochemical and genetic research and advances in electron microscopy enabled further classification.

4. At present most authorities classify all living and extinct organisms into either a five-kingdom system or a four-kingdom system. The five-kingdom system recognizes Animalia, Plantae, Monera, Fungi, and Protista (basically all eukaryotic microorganisms - i.e., algae, protozoans, and slime molds), and the four-kingdom system recognizes only the kingdoms Animalia, Plantae, Monera, and Virus; i.e., while recognizing the separation of the eukaryotes and prokaryotes, the four-kingdom system places the protozoans with the animals and the fungi and algae with the plants. The main subordinate taxa are successively the phylum (or division for plants), class, order, family, genus, and species. The basic units of the classificatory system are readily recognizable kinds, or species.

(Encyclopedia Britannica) Определите, является ли утверждение:

Species are the key elements of biological classification.

Варианты ответов:

1. истинным

2. ложным

3. в тексте нет информации

Дата добавления: 2014-12-12 | Просмотры: 608 | Нарушение авторских прав