The word "virus" in Latin means "poison." This name was used as a designation of those organisms that cause infection.
The first non-bacterial agent in 1892 was described by Dmitry Ivanovsky, who studied diseases of tobacco plants. Later, mankind discovered the first virus - tobacco mosaic.
Since then, a new era has begun in microbiology, full of discoveries. However, so far these mysterious creatures have not been fully explored.
10. Plant viruses are harmless to animals, and most animal viruses are safe for humans.
Viruses are specific. This means that they are genetically programmed for life only in a certain circle of organisms. Among them are capable of reproduction and development in plant cells. The reason is that their genetic material is suitable for the construction of plant cells. Such viruses cannot infect animals.
Likewise, the majority of those “settled” in animals cannot function in human cells, because they are not adapted to them.
However, there are always exceptions. An example of this is rabies virus. The disease is transmitted to humans from sick animals and requires immediate treatment.
9. Viruses are the most numerous biological objects on Earth.
This is the most common biological form on our planet. The diversity of these non-cellular agents is enormous, they are everywhere.
There are a number of viruses that infect bacteria, plants, animals, fungi, and so on. And each of these species evolves non-stop, creating new strains, and sometimes even settles in its owners for a long time, changing their DNA.
8. Amoeba are “free diners” for viruses
Amoebas capture food particles and consume them. In the amoeba itself, viruses often live. Since they are not able to eat on their own, they use the beneficial substances of amoeba in order to live.
7. Large viruses (mamaviruses) exceed even some bacteria
Mamaviruses got their name from the fact that they belong to mimiviruses, but exceed them in size. However, they are no longer just mimiviruses, but also fairly large bacteria.
Like mimiviruses, this species was found in the amoeba and was first confused with cocci causing pneumonia. Only at the end of the 20th century did scientists discover the viral nature of this creature.
6. Mimivirus is named so because it mimics the behavior and structure of bacteria
The name mimivirus comes from "mimicking a microbe." This species belongs to giant viruses. But in fact, this is a new non-systematic form of life that cannot be attributed to either viruses or bacteria. This species has an extremely complex genome; no other virus can compare with it.
The first similarity to bacteria is that the mimivirus is as big as they are. It is also capable of synthesizing protein, although viruses are usually not capable of this. This "creature" is stained by the Gram method, which only bacteria are capable of. In addition, he has flagella characteristic of protozoa or prokaryotes.
5. Australians tried to deal with bred rabbits with the help of myxomatosis virus
Hares and rabbits in Australia are an invasive, that is, artificially imported, animal species. It quickly spread and caused serious damage to local agriculture. Almost no methods of getting rid of rabbits were effective, so in the 1950s people spread the myxoma virus.
Rabbits were affected by myxomatosis, an acute disease in which animals acquired conjunctivitis and tumors in different parts of the body. The spread of myxoma reduced the number of rabbits from 600 to 100 million. Nevertheless, many surviving animals developed resistance to the causative agent of the disease, as a result of which the population recovered to 300 million.
4. To date, more than 2000 variants of the influenza virus are known.
Influenza is one of the most common types of SARS. He is extremely fast moving around the world and evolving. As a result of this, more than 2,000 strains of the influenza virus are now known.
3. Viruses are not living things.
Scientists cannot decide whether to take “these entities” for living organisms or for dead nature. The cellular structure is considered the most important sign of any living organisms.
The virus is a non-cellular structure. However, it does have hereditary material in the form of a DNA or RNA molecule. When it enters a foreign organism, this “creature” behaves like a living creature.
Viruses are as susceptible to natural selection as any other creature. However, they do not live on their own and are not able to independently convert food into energy. They begin to function and multiply only in the host cells.
2. Approximately 2/5 of human DNA consists of the remains of ancient viruses
According to various sources, from 8 to 40% of our DNA are traces of viruses that once infected our ancestors. Retroviruses can implant in our genome. Thus, HIV takes root in the body. But there is nothing to fear: the human genome contains mutated remains of old viruses that are unable to create a new infection in the body.
1. The virus protects the human embryo from the immune system of women
Immunity destroys any foreign cells (antigens) that it can recognize. Proteins called chemokines, which cause inflammation, contribute to this. Where this protein is, T cells gather, they destroy the antigens.
The cells of the embryo that enter the bloodstream of the mother are also determined by the body of a woman as strangers. However, for some reason the embryo itself is not recognized as a threat. This is due to the fact that during pregnancy a special membrane is formed in the uterus that does not produce a protective protein. Thus, this shell serves as a shield for the unborn child.
DNA is changed in the cells of this membrane, which affects the production of chemokine. Perhaps this is due to the activity of a virus, but it has not been proven.
Scientists at Stanford University also discovered in the cells of the embryo the ancient HERVK virus, which prevents other infections from entering the body. This protects the fetus from infectious diseases like flu.