Viruses are made up of genetic material that is in a tiny baglike area of protein. Viruses cannot reproduce and they do not grow on their own.

Viruses cannot take in energy and they do not eat or use sunlight to make food. They also do not move, and they have to be carried through body fluids, water, food, air or passed from one place to the other.

Living or Non-living

Even though they are not considered “living,” they do share characteristics of living things. For example, viruses contain DNA so they can reproduce if a cell that is living helps them reproduce.

Viruses can even evolve over time and they can become resistant to medication and this is why viruses are so dangerous.

Disease Causing Viruses

Viruses cause diseases such as colds, the flu, herpes, and other diseases.

Some viruses that cause diseases are called rhinoviruses and these kinds of viruses cause colds and the herpesvirus causes cold sores and fever blisters.

One virus, the human immunodeficiency virus or HIV causes Aids.

Classification of Viruses

Viruses are considered living, but they are not living so a virus does not fit in any of the five categories of classification.

Because viruses are so small, they have to be viewed with a microscope and they are sometimes associated as harmful, but sometimes they do good thing like kill bacteria that is bad.

Viruses have two different types of reproductive cycles, the lytic cycle and the lysogenic cycle, and viruses are sometimes classified in these two ways.

Characteristics of a Virus

Viruses have different characteristics such as they have a cell structure, but it is not organized, and they have no nucleus.

Viruses do have DNA and they have protein that protects them. Viruses are only considered active when they are inside of a living cell.

What Do Viruses Do?

Viruses are super small so they spread quickly, and they can survive in most environments.

Viruses are so small that they can even float and because of this, it is easy for a virus to be passed from one person to another person.

When a person sneezes, or coughs, the viruses are so small that they can get on other people or on other things in the environment and if they are touched, they can be picked up and the virus can cause new people to get diseases.

Facts About Viruses:

  • Viruses can die by doing good handwashing.
  • Food that is undercooked can cause a person to get a virus and get sick. These viruses are food poison.
  • Doctors are not able to treat viruses.
  • Viruses are microscopic which means they can only be seen with a microscope.
  • Virus means poison, and many viruses are the causes of diseases.
  • When a virus has RNA instead of DNA, it is called a retrovirus.

What Did You Learn?

  • What are viruses? Viruses are super tiny organisms that can make plants, animals and people sick. Viruses are made up of DNA and protein.
  • Are viruses alive? Even though people call viruses living, they are really not alive.
  • Can viruses reproduce? Viruses cannot reproduce unless something helps it to reproduce.
  • Do viruses make their own food? Viruses do not make their own food, and this is why they are considered non-living.
  • Can viruses be dangerous? Viruses can cause people to get diseases such as the flu and food poisoning viruses. Viruses can make people very sick and sometimes die.