Viruses
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A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants, and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, about 5,000 viruses have been described in detail, although there are millions of different types. Viruses are found in almost every ecosystem on Earth and are the most abundant type of biological entity. The study of viruses is known as virology, a sub-speciality of microbiology. Virus particles (known as virions) consist of two or three parts: the genetic material made from either DNA or RNA, long molecules that carry genetic information; a protein coat that protects these genes; and in some cases an envelope of lipids that surrounds the protein coat when they are outside a cell. The shapes of viruses range from simple helical and icosahedral forms to more complex structures. The average virus is about one one-hundredth the size of the average bacterium. Most viruses are too small to be seen directly with a light microscope. The origins of viruses in the evolutionary history of life are unclear: some may have evolved from plasmids – pieces of DNA that can move between cells – while others may have evolved from bacteria. In evolution, viruses are an important means of horizontal gene transfer, which increases genetic diversity. Viruses spread in many ways; viruses in plants are often transmitted from plant to plant by insects that feed on the sap of plants, such as aphids; viruses in animals can be carried by blood-sucking insects. These disease-bearing organisms are known as vectors. Influenza viruses are spread by coughing and sneezing. Norovirus and rotavirus, common causes of viral gastroenteritis, are transmitted by the faecal-oral route and are passed from person to person by contact, entering the body in food or water. HIV is one of several viruses transmitted through sexual contact and by exposure to infected blood. The range of host cells that a virus can infect is called its "host range". This can be narrow or, as when a virus is capable of infecting many species, broad. Viral infections in animals provoke an immune response that usually eliminates the infecting virus. Immune responses can also be produced by vaccines, which confer an artificially acquired immunity to the specific viral infection. However, some viruses including those causing AIDS and viral hepatitis evade these immune responses and result in chronic infections. Antibiotics have no effect on viruses, but several antiviral drugs have been developed. From Wikipedia under the
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GNU Free Documentation License Matching Results for Viruses:Richard DawkinsThe second requirement of a virus-friendly environment – that it should obey a ... Like computer viruses, successful mind viruses will tend to be hard for their ... Rosalind Franklin Rosalind Elsie Franklin (July 25, 1920 – April 16, 1958) was an ... contributions to the understanding of the fine molecular structures of DNA, RNA, viruses, coal and graphite. ... System Shock Then alter those left alive with mutagen viruses. Humanity is on the verge of a new era. ... I'm perfecting a mutagen virus in one of the groves that will turn ... From Wikiquote under the
GNU Free Documentation License ) saturn.med.nyu.edu 515px x 650px | 403.10kB [source page] Zebrafish Embryo Hatching Gland Viruses From Google Image Search: "viruses" vimeo.com Sun, 04 Oct 2009 02:35:00 PDT is : www.mediafire.com Rate !!! Enjoy !!! contact me : Thanks !!! ... with with with 8.5 and avg download. E-Mail hacking msn ... vimeo.com. ehow.com Mon, 06 Jul 2009 00:00:00 PDT "Hi, my name's Dave Andrews. Today I'm going to show you how to scan your computer for viruses. Let's go to our computer and I ... ehow.com. From Google Video Search: "viruses" How did viruses evolve when they are cellular parasites that cannot reproduce on their own? Q. Viruses exhibit no metabolic activity until they invade a host cell and force the host to replicate more viruses until the cell bursts. Viruses may mutate into different strains over time but how did they evolve into their present form? This is not a homework question. Asked by yes? - Wed Nov 17 07:59:05 2010 - Biology - 5 Answers - Comments A. The original viruses developed cells and it is possible that they evolved many times. I will describe describe one simple system that illustrates how there is some middle ground. Plasmids are rings of DNA, separate from the chromosome, that have an origin of replication and may have additional genes. Some plasmids carry genes that enable the bacterium to extend a process (F-pilus) to another similar bacterium and transfer a copy of the plasmid. It the process were to break off, it would still carry some DNA, and it has an end that will meet a bacterium. If that segment has a origin of replication and the ability to construct enough pilus to carry some DNA, that segment has a number of properties of a virus. The relationship operates in the… [cont.] Answered by novangelis - Wed Nov 17 08:38:08 2010 What are all the ways that computers can get viruses?
Q. Like for example entering an unsafe website can get you a virus. Is that the only way you can get a virus, by clicking on a bad link? Can viruses happen at any given time, or just when you click a bad link? Asked by Thank You Edge (YWWA) - Sat Apr 10 21:13:48 2010 - Security - 6 Answers - Comments A. Bad things (viruses included) can come from anywhere. For example, it can be found on the CD's from Sony/BMG you buy at Wally-mart and Bestest Buy: Novell once sent out a virus on it's update disks back in the early 90's: You need to read this article called "The six dumbest ideas in computer security" by an expert in the security field (Marcus Ranum) and then we'll talk some more: When asked about which anti-virus is best, people will always say "what I use is best" because, well, it's the one THEY picked. No matter which one they/you pick, according to that article above ALL of the antiviral programs others suggest (free or not) have two major flaws in the way they handle security: #1: they are ALL "Default… [cont.] Answered by c0nfuted - Sun Apr 11 08:32:26 2010 From Yahoo Answer Search: "viruses" |
Huffington Post Wed, 26 Oct 2011 09:47:28 -0700 It seems that whatever viruses are being covered by the vaccine, there's the one that's isn't that gets you. seventeengeese: I'm with you. It seems that whatever viruses are being Well, here are some facts. The flu vaccine is actually several in one, ... Market Watch (press release) Mon, 24 Oct 2011 06:27:59 -0700 The Anyplex II RV16 Detection Assay is the only multiplex real-time PCR (polymerase chain reaction) test that can simultaneously detect 16 of the most common respiratory viruses from a wide range of specimen types, such as nasopharyngeal aspirates and ... From Google News Search: "viruses" news.softfreedownload.org admin Wed, 29 Dec 2010 04:01:06 GMT How do you delete . viruses. from kaspersky anti virus? ok so i have Kaspersky anti virus and there were 3 events detected and how do you qurantine them? i tried clicking on the button that said quarantine but it doesn't help, ... Software News geekosystem.com Jamie Frevele Tue, 28 Dec 2010 21:27:40 GMT According to a recent report by computer security company McAfee, Mac OS X and iOS may become juicier targets for cybercriminals in 2011. Per the report, more and more companies and consumers are using Apple computers and mobile devices ... Geekosystem From Google Blog Search: "viruses" colloidalsilverkillsviruses.com While there is no argument that colloidal silver is the world s most powerful natural antibacterial and antifungal agent, the ability of colloidal silver to protect ... colloidalsilverkillsviruses.com secretguide.net A computer virus is a program that purposely does mischief and manages to copy itself to other computers, so the mischief spreads. Since computer viruses are malicious ... www.secretguide.net/read/index.php?filename=viruses From Bing Web Search: "viruses" Kids: School Time: Science: Scientists ... See also: Kids: School Time: Science: Living Things: Bacteria and Viruses (7) A Science Odyssey: Paralyzing Polio [ ] - Brief history of Salk's ... Kids: Health: Conditions and Diseases: SARS See also: Kids: School Time: Science: Living Things: Animals: Mammals: Humans: Immune System (5) Kids: School Time: Science: Living Things ... Computers: Security: Malicious Software ... Last update: Sunday, August 16, 2009 9:37:06 PM EDT - edit
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