Search results
Results from the WOW.Com Content Network
Marine microorganisms are defined by their habitat as microorganisms living in a marine environment, that is, in the saltwater of a sea or ocean or the brackish water of a coastal estuary. A microorganism (or microbe) is any microscopic living organism or virus, which is invisibly small to the unaided human eye without magnification ...
Marine viruses are defined by their habitat as viruses that are found in marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. Viruses are small infectious agents that can only replicate inside the living cells of a host organism , because they need the replication machinery of the host to ...
As the density of the human population has increased the incidence of sewage contamination of water has increased as well, thus the risk to humans from pathogenic viruses will increase if precautions are not taken. [3] Scientific studies suggest that the most common viruses found are caliciviruses, astroviruses and enteric viruses.
Viral shunt was first described in 1999 by Steven W. Wilhelm and Curtis A. Suttle. [6] Their original paper has since been cited over 1000 times. [7] For his contributions to understanding of viral roles in marine ecosystems, Suttle has received numerous awards, including being named a Fellow of the Royal Society of Canada, receiving the A.G. Huntsman Award for Excellence in Marine Science ...
Viruses are found wherever there is life and have probably existed since living cells first evolved. [106] The origin of viruses is unclear because they do not form fossils, so molecular techniques have been used to compare the DNA or RNA of viruses and are a useful means of investigating how they arise.
An archaeal virus is a virus that infects and replicates in archaea, a domain of unicellular, prokaryotic organisms. Archaeal viruses, like their hosts, are found worldwide, including in extreme environments inhospitable to most life such as acidic hot springs, highly saline bodies of water, and at the bottom of the ocean. They have been also ...
However, some scientists argue that viruses neither evolve nor self-reproduce. Instead, viruses are evolved by their host cells, meaning that there was co-evolution of viruses and host cells. If host cells did not exist, viral evolution would be impossible. As for reproduction, viruses rely on hosts' machinery to replicate.
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.