Viruses are the example of nanotechnology by nature. Their size ranges between 20 nanometers (0.0002 mm) to 400 nanometers (0.0004 mm). The smaller known virus till to date is Circovirus (usually affect animal causing PCVD) and the biggest one is mimivirus (the causative agent of some form of Viral Pneumonia) which is even bigger than some smaller bacteria. There are even bigger virus discover called mamaviru.
There are millions of viruses in a single drop of water, account for 1031 total viruses on the Earth. If calculated by the total number and the average size of virus (200 nanometers) all of them (lined up end to end) will stretch 108 Light years into space (2 times more than the diameter of Milky Way).
3. Living or Dead
Viruses are neither living nor dead entity. They are among the border line of Live and dead. They don’t have their own food metabolism mechanism; they can’t produce energy by their own. But due to ability to replicate (reproduce) themselves Viruses, by some scientist, considered as living thing. Although they can’t reproduce outside the host cell
4. Temperature Does matter for Virus
On average, viruses live on 37 0C for seconds, for minutes on 20 0C, for hour on 10 0C for days on 0 0C and for years on temperature in minus. The hotter temperature of your body during viral infection helps immune system to get rid of viruses. On the other hand, in cold weather, you have more chances to get flu. There are still many ancient viruses living in sub freezing temperature of Antarctica.
5. Wide Range Of Host
Viruses are not only the worst enemy of human; they can infect every living organism under the Sun. The virus nature of more rapid genetic diversion enables them to parasitize all groups of Living organisms. Their range of hosts not only limited to men but include animal, plants, insects, Bacteria (infected by Bacteriophages), fungi, protozoa, amoebae their own relatives, yes there are viruses (viriophage) which infect other viruses.
6. First written Proof of Viral Disease
The first written evidence of a viral infection is dated back to ancient Egypt (3700 B.C), which shows a patient with typical clinical features of poliomyelitis. The first ever discovered virus is Tobacco Mosaic Virus (TMV) discovered by a Russian Microbiologist, Dmitry Ivanovsky in 1892. The first discovered virus causing disease in Human is Yellow Fever virus, discovered by Walter Reed in 1901. Structure of Virus was not been observed until the invention of Electron Microscope in 1931. Ernst Ruska and Max Knoll (both are Germen Engineers) were the first who observe Virus under Electron Microscope.
7. DNA Vs. RNA Virus
On the basis of genetic material (Ribonucleic acid), Viruses are classifying as either DNA (Double Strand Nucleic Acid) or RNA (Single Strand Nucleic Acid) viruses. Among these types, DNA viruses are stable and while replicating, they make good copies of their genetic material. This can be useful to make vaccines against them. On other hand, RNA viruses are less stable, their genetic material changes quickly due to which it’s hard to make vaccine against them or get vaccinated against the same viral infection repeatedly. (Can you guess HIV belongs to which class?)
8. Antiviral Drugs – Pseudo Genetic Codes
Antiviral drugs (such as Acyclovir) are Pseudo (fake) genetic material which is perceived and adopted by viruses as their own replicated genetic martial (RNA or DNA) in cell, using which render the viruses harmless.
9. Social History of Virus
Traces of Viruses found in ancient human skeleton are used by scientist as a tool or evidence to uncover pre-historic migration by human being. Scientists are tracing prehistoric migration by viruses they carry with themselves.
10. Friendly Virus
Despite all the harmful effects of virus, there is a useful Medical use of Viruses. They are being used in gene therapy as gene delivery systems for the treatment of various inherited and acquired diseases.
Viruses are the enemy of our enemies (bacteria, Fungi, Protozoa), they helping us by killing them as well.