The broadest taxonomic category is "life," and viruses do not fit easily into this category. They do not pass the very basic test for life: they are not made of cells. They also do not reproduce on their own, they do not respond to stimuli, and they do not have their own metabolism. A virus is defined as an infectious agent--its not even called a cell. There isn't a consensus, though. Scientists are still arguing whether viruses are alive since they can multiply and thrive just like a living organism.
So why is the study of viruses so important? Watch the video to find out.
Have you ever heard someone use the catchphrase, "It's gone viral"? It's come to represent the situation when a something passes from person to person until there are thousands of "hits" or "views" of the image or video. But, have you ever thought of how we got that phrase in the first place? The phrase actually is based off how a virus works. A virus is called an infectious agent. It takes over a cell, and multiplies inside it. Each cell that it takes over and kills can release many virus particles. There are over 4000 types of viruses that scientists have documented, so they are not to be neglected in our studies, especially since they can be so damaging to the host. They can live inside plants and animals—and that includes humans too. You as the host can suffer with short-term discomfort or even long-term damage. They can even live inside you without symptoms until they have already taken over your system. Virus can also kill—over the past three decades more than 20 million people have died due to the human immunodeficiency virus that causes AIDS. So, we need to fight them. They not only can cause damage to humans, they can invade plants and animals too… which can cost billions. Believe it or not, some scientists are still debating whether they are alive or dead. We still have so much to learn.
Question
What is the main reason scientists believe that viruses are not living organisms?
