virus ...

A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting ******* plants and the discovery of the ******* mosaic virus by Martinus Beijerinck in 1898, more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology.
When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or virions, consisting of (i) the genetic material, i.e., long molecules of DNA or RNA that encode the structure of the proteins by which the virus acts; (ii) a protein coat, the capsid, which surrounds and protects the genetic material; and in some cases (iii) an outside envelope of lipids. The shapes of these virus particles range from simple helical and icosahedral forms to more complex structures. Most virus species have virions too small to be seen with an optical microscope and are one-hundredth the size of most bacteria.
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 in a way analogous to sexual reproduction. Viruses are considered by some biologists to be a life form, because they carry genetic material, reproduce, and evolve through natural selection, although they lack the key characteristics, such as cell structure, that are generally considered necessary criteria for defining life. Because they possess some but not all such qualities, viruses have been described as "organisms at the edge of life", and as replicators.Viruses spread in many ways. One transmission pathway is through disease-bearing organisms known as vectors: for example, viruses are often transmitted from plant to plant by insects that feed on plant sap, such as aphids; and viruses in animals can be carried by blood-sucking insects. Many viruses, including influenza viruses, SARS-CoV-2, chickenpox, smallpox, and measles, spread in the air by coughing and sneezing. Norovirus and rotavirus, common causes of viral gastroenteritis, are transmitted by the faecal–oral route, passed by hand-to-mouth contact or in food or water. The infectious dose of norovirus required to produce infection in humans is fewer than 100 particles. HIV is one of several viruses transmitted through sexual contact and by exposure to infected blood. The variety of host cells that a virus can infect is called its "host range". This can be narrow, meaning a virus is capable of infecting few species, or broad, meaning it is capable of infecting many.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. Some viruses, including those that cause HIV/AIDS, HPV infection, and viral hepatitis, evade these immune responses and result in chronic infections. Several classes of antiviral drugs have been developed.

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  1. M

    Help Ano ibig sabihin nito

    P help po ano ibig sabihin nito, kc kada bukas ko ng pc ganyan agad nag popup , baka virus to pa help kong paano e remove yan
  2. G

    Closed Mga bossing tanong lang tungkol sa mga virus sa cp

    Nagdodownload po kasi ako ng mga movie sa cp ko pero hindi torrent, yung mga nakikita ko dito sa forum sa openload. May chance bang magka virus cp ko. Binubura ko din agad katapos kong panoorin e
  3. V

    Closed Shingles or Kulebra

    Anu kaya mabisa na gawin para mawara yung pain or kati ..napakasakit kasi huhu
  4. I

    Closed Trojan virus

    Pano po ba mawala ang virus nato pa help po mga paps
  5. J

    Closed Help virus

    Hello po mga kababayan May nag po-pop na html sa Laptop ko pag open palang di ko pinapansin ine-exit ko lng pero nalaman ko di na gumagana ung "cmd" (command prompt) nag shutdown nlang.. Please help me and thanks.
  6. U

    Closed Suggest po kayo ng trusted site na pwedeng pagdownloadan ng mga android apps.

    apkpure.com lang ang alam ko at doon lang ako kumukuha, trusted site ba ito?
  7. A

    Closed Bakit ganon high risk yun ibang mga vpn

    Bakit ganon may virus yun ibang vpn kasi kapag nagiinstall ako na dedetect ng cp ko na may virus tatlo yun antivirus ko .high risk s†éál sms rogue behavior . pero may iba akong vpn na nakapasa sa tatlo kong antivirus .. yung wang vpn saka tart vpn na install ko virus detected .. nakalagay
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