Virus multiplication cycle + 40 facts about virus

Characteristics of viruses
   
-They do not have an organized cell structure
-They have no cell nucleus
-They typically have one or two strands of DNA or RNA
-they are covered with a protective coat of protein called CAPSID
-they are inactive when not inside a living cell ,but are active when inside another living cell

40 fact about virus

1. The name virus was in fact coined from the Latin word meaning slimy liquid or poison.
2. Viruses are simpler than bacteria, made up of genetic code (DNA or RNA) with a protein shell .
3. A virus that contains RNA instead of DNA is called a retrovirus. Amazingly our body has about 8% retrovirus genes passed through generations.
4. Half of all human DNA originally came from viruses, which in factinfected and embedded themselves in our ancestors’ egg and sperm cells.
5. Viruses are not alive .They are inanimate complex organic matter. They lack any form of energy, carbon metabolism, and cannot replicate or evolve on it’s own.
6. Viruses can’t reproduce on their own . They need to take over another cell (plant, animal or human).
7. They do not have an organized cell structure.They have no cell nucleus. They typically have one or two strands of DNA or RNA. They have a protective coat of protein called capcid.
8. Viruses are not classified in any of the five kingdoms of living things. This in fact means they are not bacteria, fungi, protozoa, plants, or animals.
9. Virus particles form regular geometric shapes, even though the proteins from which they are made are irregularly shaped.
10. Viruses are in fact  20 to 400 nanometres in size.
11. The biggest known viruses are mimiviruses, which are 400 nanometers (0.0004 millimeters) in diameter. The viral genome is 1,200,000 nucleotides in length and codes for over 900 proteins.
12. The smallest known viruses are circoviruses, which are 20 nanometers (0.00002 millimeters) in diameter. The viral genome is 1,700 nucleotides in length and codes for two proteins.
13. For every organism on this planet, there are at least 10 viruses, probably more. Over 4,000 viruses have been identified so far.
14. Viruses in fact make up the single largest component in the Oceans.
15. There are a million virus particles per ml of seawater for a global total of 1031 virions!
16. Amazing fact is if they are lined up end to end (Size 200 Nanometers) , they would stretch 200 million light years into space. Almost 200 times farther than the Andromeda Galaxy! And 2000 times longer than the diameter of the whole Milky Way!
17. On average, viruses live on 370 C for seconds, for minutes on 200 C, for hour on 100 C ,for days on 0 0C and for years on temperature in minus.
18. 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.
19. 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.
20. The first ever discovered virus is Tobacco Mosaic Virus (TMV) discovered by a Russian Microbiologist, Dmitry Ivanovsky in 1892.
21. The first discovered virus causing disease in Human is Yellow Fever virus, discovered by Walter Reed in 1901.
22. Structure of Virus was not observed until the invention of Electron Microscope in 1931.
23. On the basis of genetic material (Ribonucleic acid), Viruses are classified 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. This is why flu vaccine is needed every year.
24. Many viruses cause disease, viruses cause colds, flu, chickenpox, measles, mumps, rubella, polio, rabies, hepatitis, yellow fever. HIV which causes AIDS, is a virus.
25. Unlike bacterial infection, it is very hard to treat viral infections. Antibiotics don’t help.
26. Viral infections cannot be cured with antibiotics . Most viral infections, like a cold or flu, or some chest infections, get better on their own with the help of our body immune systems.
27. It is estimated that 50% of children in the USA have had EBV (Epstein Barr Virus) , the virus responsible for mononucleosis  and between 90-95% of adults are carriers.
28. Once infected, people become carriers of the EBV(Epstein Barr Virus)  for life, though not everyone will experience symptoms.
29. Once people have had some viral infections, like chickenpox, it makes them immune from having it again . Vaccination creates the same kind of immunity, so can prevent people from getting the viral infections.
30. More the people who are vaccinated , less the amount of infection in a population, protecting even those people who are not vaccinated . This is called ‘herd immunity’. Depending on the virus, 85-95% of people need to be vaccinated to protect the rest of the people.
31. There is no vaccine against colds, as there are so many different viruses that cause colds.
32. The Spanish Flu is the most well-known pandemic of the flu . It amazingly killed anywhere from 40 to 100 million people from 1918 to 1920. The first human influenza (Flu) virus was isolated in 1933.
33. In 2005, the 1918 pandemic influenza virus strain was constructed from nucleic acid sequence obtained from victims of the disease.
34. When we have a cold and cough the virus particles can travel at 320 kilometres an hour and up to 900 metres. That is faster than a passenger jet at takeoff!
35. The HIV-1 genome, which is about 10,000 nucleotides long, can exist as 106020different sequences. To put this number in perspective, there are 1011 stars in the Milky Way galaxy and 1080 protons in the universe.
36. Amoebas turn out to be great places to seek out new viruses. They like to swallow big things and so serve as a kind of mixing bowl where viruses and bacteria can swap genes.
37. Some viruses are useful – viruses called bacteriophages (means ‘bacteria eater’) kill bacteria and are used to protect people against harmful bacteria in food.
38. 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.
39. Plants can get virus infections . They can make leaves and flowers change colour, or make leaves and stems twisted.
40. Some parasitic wasps lay eggs in caterpillars, where they mature into adult wasps. The wasp eggs contain a virus, encoded in the wasp genome, which prevents the caterpillar from rejecting the eggs.