types of viruses

A virus is a miniscule pocket of protein that contains genetic material. If you placed a virus next to a bacterium, the virus would be dwarfed. For example, the polio virus is around 50 times smaller than a Streptococci bacterium, which itself is only 0.003mm long. Viruses can be described as either RNA or DNA viruses, according to which type of nucleic acid forms their core. 

The four main types of virus include:

Icosahedral – the outer shell (capsid) is made from 20 flat sides, which gives a spherical shape. Most viruses are icosahedral.

Helical – the capsid is shaped like a rod.

Enveloped – the capsid is encased in a baggy membrane, which can change shape but often appears spherical.

Complex – the genetic material is coated, but without a capsid.

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(Useful for UPSC General Studies, APPSC Group 1 Group 2 , Mains Material, Paper 1, Paper 4 Section 1 Section 2 Section 3, ROLE AND IMPACT OF SCIENCE AND TECHNOLOGY IN THE DEVELOPMENT OF INDIA, GENERAL AWARENESS WITH THE MODERN TRENDS IN LIFE SCIENCES, DEVELOPMENT & ENVIRONMENT PROBLEMS)