In everyday life, we often hear the term “virus”. We know a virus as a material/gene that can cause infection in living things. Viruses may grow and live in human, animal and plant living cells. At first, a virus was thought to be a toxic chemical; it also caused this gene to be called a virus, which in Greek means "poison".

In the late 1800s, based on the nature of viruses that could cause various diseases and spread among organisms, the researchers argued that viruses had some similarities to bacteria, and proposed viruses as the simplest form of life.

A virus is a very small infectious agent which requires a microscope to see it. A virus does not have any cell nucleus and some other organelles such as cells in general, which makes the virus in a grey area between living organisms or chemicals. The virus is parasitic so that it can only replicate and multiply inside its host cell.

The size of the virus is between 25 - 300 nm. The smallest virus is the polio virus with a size of 25 nm, while the largest one is the tobacco virus (tobacco mosaic virus) which is 300 nm. There are some variations regarding the form of viruses; some are round, stems, and some have a "T" shape. Influenza virus and HIV (the virus that causes AIDS) are examples of round-shaped viruses, TMV is a rod-shaped virus, while a T-shaped virus is a virus that attacks bacteria.

Some viruses, such as influenza viruses, human deficiency virus (HIV), viral hepatitis, Ebola virus and others may cause harm to humans by causing diseases. However, the virus can also be used for positive purposes, for instance in the field of genetic engineering such as gene cloning or gene therapy for humans to overcome genetic diseases such as diabetes and cancer.

With the effect of infection/disease caused by a virus, it is necessary to prevent viral infections. One step that may be done is by giving vaccines. Today, giving vaccines is still regarded as one of the most effective ways to avoid viral infections.

Text by Rezky Zakiri
Stock photos from Google Search Images

Source(s):

• Campbell, N., Reece, J., Mitchel, L. G. (2010). Biology 9th ed. Jakarta: Erlangga
• Aryulina, D. (2010). Biologi 1. Jakarta: Esis.
• Melaty, A. & Fadil, I. A. D. (2017). EPIDEMI HUMAN IMMUNODEFICIENCY VIRUS (HIV) SEBAGAI POTENSI ANCAMAN BIOWEAPONS & BIOTERRORISM DI ASIA TENGGARA: Jurnal Ilmu politik dan komunikasi Vol: VII No.2.