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Amazing Facts About Viruses

Удивительные факты о вирусах

Virus (lat. Virus - poison) is a non-cellular infectious agent that can be reproduced only inside living cells. Viruses infect all types of organisms, from plants and animals to bacteria and archaea (bacterial viruses are commonly called bacteriophages). Viruses capable of replicating only in the presence of other viruses (satellite viruses) have also been detected.

Are there really giant viruses that are larger than bacteria? Is it true that 2/5 of human DNA consists of the remnants of ancient viruses that infected the cells of our ancestors at different stages? It will be really interesting ... Plant viruses are harmless to animals, and most animal viruses are safe for humans.

Удивительные факты о вирусах

Viruses are not living things. They don’t have cells, they don’t know how to convert food into energy, and without a “host” these are just small clots of chemicals. Viruses are also not something dead - they have genes, they multiply, natural selection processes operate for them.

Удивительные факты о вирусах

It is believed that approximately 2/5 of human DNA consists of the remains of ancient viruses that infected the cells of our ancestors at different stages.

Удивительные факты о вирусах

To date, more than 2,000 variants of the influenza virus are known, which differ in antigenic spectrum.

Удивительные факты о вирусах

In 1859, an Australian farmer brought rabbits from England to create a small population and hunt them. The absence of natural enemies and ideal conditions for life and breeding year round became the reason for the uncontrolled growth of the rabbit population, which led to the extinction of many species of local plants. They tried to deal with rabbits by shooting, burrowing holes, poisons, building mesh barriers, but it's all useless. Finally, in the middle of the 20th century, the myxomatosis virus was spread among them, which reduced the population from 600 million to 100 million. However, the surviving individuals acquired genetic resistance to the virus and again began to actively multiply.

Удивительные факты о вирусах

Viruses are undoubtedly the most numerous biological objects on Earth, and in this indicator they surpass all organisms combined.

Удивительные факты о вирусах

Large-sized viruses are called mamaviruses. Their dimensions often exceed the dimensions of even some bacteria. Such viruses have satellite viruses.

Удивительные факты о вирусах

The so-called mimivirus is named so because it mimics the behavior and structure of the bacterium. Some experts believe that it is an intermediate between bacteria and viruses, others are sure that this is a separate form of life. This virus is characterized by the most voluminous and complex set of DNA among all viruses.

Удивительные факты о вирусах

In 1992, scientists traced the path to the source of pneumonia that erupted in England - it turned out to be a virus hiding inside an amoeba living in the towers of a cooling tower (cooling tower). It was so large that at first scientists took it for a bacterium.

Удивительные факты о вирусах

Amoeba for viruses are a kind of sandboxes and free eateries - they absorb large objects within their reach and are a source of nutrients for bacteria that inside the amoeba exchange genes with other bacteria and viruses.

Удивительные факты о вирусах

Instead of poison, the braconids introduce a virus to their victims that suppresses the victim’s immune system. Suppressed immunity allows the parasitic maggot larva to develop inside the victim. Biologists have found that this virus is more than a hundred million years old, and most likely it has merged with wasp DNA.

Удивительные факты о вирусах

When an embryo forms inside a woman, the immune system recognizes the new nucleation as something foreign. Thanks to the DNA of the virus, which encodes proteins, the fetus is not threatened by the immune system.

Virus (lat. Virus - poison) is a non-cellular infectious agent that can be reproduced only inside living cells. Viruses infect all types of organisms, from plants and animals to bacteria and archaea (bacterial viruses are commonly called bacteriophages). Viruses capable of replicating only in the presence of other viruses (satellite viruses) have also been detected.

Since the publication in 1892 of an article by Dmitry Ivanovsky describing the non-bacterial pathogen of tobacco plants and the discovery in 1898 by Martin Beyerink of the tobacco mosaic virus, more than 6 thousand types of viruses have been described in detail, although it is estimated that there are more than one hundred million of them. Viruses are found in almost every ecosystem on Earth, they are the most numerous biological form. The study of viruses is the science of virology, a section of microbiology.

While the virus is in the extracellular environment or in the process of infection of the cell, it exists as an independent particle. Viral particles (virions) consist of two or three components: genetic material in the form of DNA or RNA (some, such as mimiviruses, have both types of molecules); the protein membrane (capsid) that protects these molecules, and, in some cases, additional lipid membranes. The presence of a capsid distinguishes viruses from virus-like infectious nucleic acids - viroids. Depending on what type of nucleic acid the genetic material is represented, DNA-containing viruses and RNA-containing viruses are isolated; Baltimore classification of viruses is based on this principle. Prions were also mistakenly classified as viruses, but later it turned out that these pathogens are special infectious proteins and do not contain nucleic acids. The shape of viruses varies from simple helical and icosahedral to more complex structures. The size of the average virus is about one hundredth of the size of the average bacterium. Most viruses are too small to be clearly visible under a light microscope.

Viruses are obligate parasites, as they are not able to multiply outside the cell. Outside the cell, viral particles do not show signs of life and behave like particles of biopolymers. Viruses differ from living parasitic organisms by the complete absence of basic and energy metabolism and the absence of the most complex element of living systems - the translation apparatus (protein synthesis), the degree of complexity of which exceeds that of the viruses themselves

The appearance of viruses on the evolutionary tree of life is unclear: some of them could be formed from plasmids, small DNA molecules that could be transmitted from one cell to another, while others could come from bacteria. In evolution, viruses are an important means of horizontal gene transfer, causing genetic diversity. Some consider viruses to be a special form of life, as they have genetic material, are capable of creating viruses of their own, and evolve through natural selection. However, viruses lack important characteristics (such as cell structure), without which they cannot be classified as living. Since they possess some, but not all, properties, viruses are described as “organisms on the edge of life.”

Viruses spread in many ways: plant viruses are often transmitted from plant to plant by insects that feed on plant juices, such as aphids; animal viruses can be spread by blood-sucking insects, such organisms are known as carriers. Influenza virus spreads by coughing and sneezing. Norovirus and rotavirus, usually causing viral gastroenteritis, are transmitted by the fecal-oral route through contact with contaminated food or water. HIV is one of several sexually transmitted viruses and transfusions of infected blood. Each virus has a specific host specificity, determined by the types of cells that it can infect. The host circle may be narrow or, if the virus infects many species, wide.

In animals, viral infections cause an immune response, which most often leads to the destruction of the pathogenic virus. The immune response can also be triggered by vaccines that give active acquired immunity against a specific viral infection. However, some viruses, including human immunodeficiency virus and causative agents of viral hepatitis, manage to elude the immune response, causing a chronic disease. Antibiotics do not act on viruses, however several antiviral drugs have been developed.

Are there really giant viruses that are larger than bacteria? Is it true that 2/5 of human DNA consists of the remnants of ancient viruses that infected the cells of our ancestors at different stages? It will be really interesting ...

Ротавирус

Since the publication in 1892 of an article by Dmitry Ivanovsky describing the non-bacterial pathogen of tobacco plants and the discovery in 1898 by Martin Beyerink of the tobacco mosaic virus, more than 6 thousand types of viruses have been described in detail, although it is estimated that there are more than one hundred million of them. Viruses are found in almost every ecosystem on Earth, they are the most numerous biological form. The study of viruses is the science of virology, a section of microbiology.

Since the publication in 1892 of an article by Dmitry Ivanovsky describing the non-bacterial pathogen of tobacco plants and the discovery in 1898 by Martin Beyerink of the tobacco mosaic virus, more than 6 thousand types of viruses have been described in detail, although it is estimated that there are more than one hundred million of them. Viruses are found in almost every ecosystem on Earth, they are the most numerous biological form. The study of viruses is the science of virology, a section of microbiology.

While the virus is in the extracellular environment or in the process of infection of the cell, it exists as an independent particle. Viral particles (virions) consist of two or three components: genetic material in the form of DNA or RNA (some, such as mimiviruses, have both types of molecules); the protein membrane (capsid) that protects these molecules, and, in some cases, additional lipid membranes. The presence of a capsid distinguishes viruses from virus-like infectious nucleic acids - viroids. Depending on what type of nucleic acid the genetic material is represented, DNA-containing viruses and RNA-containing viruses are isolated; Baltimore classification of viruses is based on this principle. Prions were also mistakenly classified as viruses, but later it turned out that these pathogens are special infectious proteins and do not contain nucleic acids. The shape of viruses varies from simple helical and icosahedral to more complex structures. The size of the average virus is about one hundredth of the size of the average bacterium. Most viruses are too small to be clearly visible under a light microscope.

Viruses are obligate parasites, as they are not able to multiply outside the cell. Outside the cell, viral particles do not show signs of life and behave like particles of biopolymers. Viruses differ from living parasitic organisms by the complete absence of basic and energy metabolism and the absence of the most complex element of living systems - the translation apparatus (protein synthesis), the degree of complexity of which exceeds that of the viruses themselves.

The appearance of viruses on the evolutionary tree of life is unclear: some of them could be formed from plasmids, small DNA molecules that could be transmitted from one cell to another, while others could come from bacteria. In evolution, viruses are an important means of horizontal gene transfer, causing genetic diversity. Some consider viruses to be a special form of life, as they have genetic material, are capable of creating viruses of their own, and evolve through natural selection. However, viruses lack important characteristics (such as cell structure), without which they cannot be classified as living. Since they possess some, but not all properties, viruses are described as: “organisms on the edge of life,” and as replicators.

Viruses spread in many ways: plant viruses are often transmitted from plant to plant by insects that feed on plant juices, such as aphids; animal viruses can be spread by blood-sucking insects, such organisms are known as carriers. Influenza virus spreads by coughing and sneezing. Norovirus and rotavirus, usually causing viral gastroenteritis, are transmitted by the fecal-oral route through contact with contaminated food or water. HIV is one of several sexually transmitted viruses and transfusions of infected blood. Each virus has a specific host specificity, determined by the types of cells that it can infect. The host circle may be narrow or, if the virus infects many species, wide.

In animals, viral infections cause an immune response, which most often leads to the destruction of the pathogenic virus. The immune response can also be triggered by vaccines that give active acquired immunity against a specific viral infection. However, some viruses, including human immunodeficiency virus and causative agents of viral hepatitis, manage to elude the immune response, causing a chronic disease. Antibiotics do not act on viruses, however several antiviral drugs have been developed.

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