how viruses are harmful to us
Answers
Answer:they infect us and that's why they are dangerous
Answer:
Medically reviewed by Jill Seladi-Schulman, Ph.D. — Written by Peter Crosta — Updated on June 24, 2021
What are viruses?
Sources
Transmission
When viruses change
Viral diseases
COVID-19
Tackling viruses
Treatment
Vaccines
Summary
Viruses are microscopic particles that exist almost everywhere on Earth. They are present in animals, plants, and other living organisms, and they can sometimes cause diseases.
Viruses are biological entities that can only thrive and multiply in a host, which is a living organism such as a human, an animal, or a plant. Some viruses cause disease. For example, severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2, causes the disease COVID-19.
A virus may also affect one organism in one way but a different one in another. This explains why a virus that causes illness in a cat may not affect a human.
Viruses vary in form and complexity. They consist of genetic material, DNA or RNA, with a coat of protein around it. Some have an additional coat called the envelope. This may be spiky and helps them latch onto and enter host cells. They can only replicate in a host.
In this article, we discuss in detail viruses, including how they act and how they can affect people.