Search results
Results from the WOW.Com Content Network
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.
The word bacteria is the plural of the Neo-Latin bacterium, which is the romanisation of the Ancient Greek βακτήριον (baktḗrion), [6] the diminutive of βακτηρία (baktēría), meaning "staff, cane", [7] because the first ones to be discovered were rod-shaped. [8] [9]
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).
Pathogenic bacteria are bacteria that can cause disease. [1] This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and many are beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. [2]
Bacteria are single-celled prokaryotes that range in size from 0.15 and 700 μM. [14] While the vast majority are either harmless or beneficial to their hosts, such as members of the human gut microbiome that support digestion, a small percentage are pathogenic and cause infectious diseases.
Graphic depicting the human skin microbiota, with relative prevalences of various classes of bacteria. The human microbiome is the aggregate of all microbiota that reside on or within human tissues and biofluids along with the corresponding anatomical sites in which they reside, [1] [2] including the gastrointestinal tract, skin, mammary glands, seminal fluid, uterus, ovarian follicles, lung ...
The word microbiome (from the Greek micro meaning "small" and bíos meaning "life") was first used by J.L. Mohr in 1952 in The Scientific Monthly to mean the microorganisms found in a specific environment. [59] [60]
In gram-positive bacteria, the cytoplasmic membrane is only surrounded by a thick cell wall of peptidoglycan. By contrast, the envelope of gram-negative bacteria is more complex and consists (from inside to outside) of the cytoplasmic membrane, a thin layer of peptidoglycan, and an additional outer membrane, also called the lipopolysaccharide ...