A virus is a microorganism, why does a virus invade a person s body?

Because the virus is very ferocious, after entering the human body, it will invade the immune system, causing people to lose their immunity and get sick.

Because the virus can only parasitize in such a way that if it does not invade the human body, it will die, and the human body provides external conditions for his survival.

Humans have viruses because they have been on Earth for a long time, even before the emergence of humans. Viruses are very tiny organisms that do not possess a complete cellular structure, only a genome and shell. Viruses cannot replicate on their own, but can infect other cells, inject their own DNA or RNA into the host cell, use the host cell's biosynthetic mechanism to copy their own genetic material, and cause the host cell to produce damage, so as to continue to spread its genome.

Some viruses only infect specific species of animals, unlike the plague virus, which only infects mice, while humans cannot infect them. But other viruses, such as influenza and coronavirus, can cross species barriers to infect different animal species, including humans. Viruses mutate as they multiply, which can lead to their ability to cross species barriers to infect new hosts.

In addition, humans live in the same environment as other animals, so the risk of virus transmission is also relatively high. For example, certain agricultural activities, poultry markets, or animal trading markets may bring many different species of animals together, which can help the virus infect across species.

Viruses are naturally occurring organisms that are part of the life-threatening systems that air above the Earth. Although they may pose serious health and economic risks to humans, their presence is also a counterbalance to natural systems. The measures taken include strengthening hygiene and preventive measures to reduce the spread of the virus and the harm to humans.

Human beings have viruses because viruses are microorganisms that exist for hundreds of millions of years, and they exist in various organisms and environments in nature.

Viruses exist in humans not because humans have any problems with their own sensitivities, but because viruses themselves are widespread in nature. Hope.

The struggle between humans and viruses has begun since the time of Australopithecus, and in the struggle of millions of years, the ** of human beings against viruses is developing, and viruses are also evolving, choosing the most suitable way to survive.

Many viruses have abandoned the confrontation with the human immune system, signed an armistice, and since then have settled in the human body, and the number of these viruses is not rare, reaching more than 380 trillion.

Many people may not believe it, but every surface inside and outside our body is covered in microbes--- bacteria, viruses, fungi, and many other microscopic life ---forms.

These viruses aren't the dangerous viruses you hear about often, such as those that cause the flu or the common cold, or the more sinister viruses like Ebola or dengue sylvestris.

Wen Jiantan is an inevitable product of natural co-evolution, because the excessive lethality rate will sometimes make Hu cut off the source of infection, so that he can not continue to spread, so the choice of maximizing benefits is better than "forever", they choose to survive in the human body, and naturally become a community of destiny with human beings.

Viruses are living things. Virus (English: virus, formerly known as "filter virus" in Chinese) is a non-cellular form composed of a nucleic acid molecule (DNA or RNA) and protein, which is a biological, unable to manifest life phenomena on its own, and is an organic species between living and non-living organisms that live by parasitism, it is neither living nor non-biotic, and is not currently classified in the Five Realms (prokaryotes, protists, fungi, plants and animals).

It is a piece of DNA or RNA wrapped in a protective shell, and through the mechanism of infection, these simple organisms can use the host's cellular system to replicate themselves, but cannot grow and replicate independently. Viruses can infect almost all living organisms that have cellular structures. The first known virus was the tobacco mosaic virus, discovered and named by Martinus Bergerinck in 1899, and more than 5,000 types of viruses have been identified to date.

The science that studies viruses is called virology and is a branch of microbiology.

First of all, we need to know that viruses belong to the biological kingdom. The concept of the recognized source is that viruses are non-cellular living organisms, the smallest and simplest organisms discovered so far, but all viruses must be within living cells in order to exhibit their basic life activities.

The concept of microorganisms is that organisms that are generally difficult to see with the naked eye. "Microbiology" edited by Shen Ping believes that:

Microorganisms include viruses and subviral factors that cannot live independently without cell structure, bacteria and archaea with prokaryotic cell structure, fungi with eukaryotic cell structure, unicellular algae, protists, etc.

So viruses are microorganisms.

A virus is an individual microscopic.

A small, simple non-cellular organism that contains only one nucleic acid (DNA or RNA) and must parasitize and replicate in living cells. Microorganisms include: bacteria, viruses, fungi and some small protists, microscopic algae, etc., a large group of organisms, which are small and closely related to humans.

In textbooks, microorganisms are divided into the following 8 categories: bacteria, viruses, fungi, actinomycetes, rickettsia, mycoplasma, chlamydia, and spirochetes. Some microorganisms are visible to the naked eye, such as mushrooms, reishi, shiitake mushrooms, etc., which belong to fungi.

There are also microorganisms, which are a class of "non-cellular organisms" that are made up of a few components such as nucleic acids and proteins.

Hence it is a microorganism.

It is neither prokaryotic nor eukaryotic.