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progaryotig
Значение термина progaryotig в knolik
progaryotig - progaryotig (PROKARYOTIC)
progaryotig - (Of cells or organisms), having the genetic material in the form of simple filaments of DNA (See also: Chromosome), and not separated from the cytoplasm by a nuclear membrane. The cells of bacteria and of blue-green algae are of this type, distinguishing these organisms sharply from all others (Compare with: Eucaryotic).
In one bacterium, Escherichia coliy the DNA consists of a single thread, when straightened out many times longer than the cell diameter, in the form of a closed loop. Division of the DNA during cell division is not by means of a spindle as in the mitosis of eucaryo-tic cells. Mitochondria and chloroplasts, the membrane-bounded organelles associated in other organisms with respiration and photosynthesis, are lacking. In swimming forms (which occur only in bacteria) organs of locomotion are either flagella, much simpler than those of eucaryotic cells, consisting of a single fibril; or, in spirochaetes, consist of a bundle of fibrils, the axial filament, that is wound round the cell protoplast and embedded in the cytoplasm at each end. Cell wall of procaryotic organisms is unique in containing mureins, distinctive polymers composed of certain amino acids and carbohydrates.
Рядом со словом progaryotig в knolik
| progambium | В начало буква "" буквосочетание "" | prochordata |
Статья про progaryotig была прочитана 202 раз
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