Search results
Results from the WOW.Com Content Network
Non-cellular life, also known as acellular life, is life that exists without a cellular structure for at least part of its life cycle. [1] Historically, most definitions of life postulated that an organism must be composed of one or more cells, [2] but, for some, this is no longer considered necessary, and modern criteria allow for forms of life based on other structural arrangements.
Microbiology (from Ancient Greek μῑκρος (mīkros) 'small' βίος (bíos) 'life' and -λογία 'study of') is the scientific study of microorganisms, those being of unicellular (single-celled), multicellular (consisting of complex cells), or acellular (lacking cells).
Cellular microbiology is a discipline that bridges microbiology and cell biology. The term "cellular microbiology" was coined by the authors of the book of the same title published in 1996. [ 1 ] Cooperation and mutual dependency between microbiology and cell biology had been increasing in the years before that, and the emergence of a new ...
The widespread prevalence of these repair processes indicates the importance of maintaining cellular DNA in an undamaged state in order to avoid cell death or errors of replication due to damage that could lead to mutation. E. coli bacteria are a well-studied example of a cellular organism with diverse well-defined DNA repair processes.
Bacteria can be classified on the basis of cell structure, cellular metabolism or on differences in cell components, such as DNA, fatty acids, pigments, antigens and quinones. [117] While these schemes allowed the identification and classification of bacterial strains, it was unclear whether these differences represented variation between ...
A microorganism, or microbe, [a] is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells.. The possible existence of unseen microbial life was suspected from ancient times, such as in Jain scriptures from sixth century BC India.
Cell theory has traditionally been accepted as the governing theory of all life, [1] but some biologists consider non-cellular entities such as viruses living organisms [2] and thus disagree with the universal application of cell theory to all forms of life.
Pelagibacter ubique is one of the smallest known free-living bacteria, with a length of 370 to 890 nm (0.00037 to 0.00089 mm) and an average cell diameter of 120 to 200 nm (0.00012 to 0.00020 mm). They also have the smallest free-living bacterium genome: 1.3 Mbp , 1354 protein genes, 35 RNA genes.