Microorganisms including viruses are a significant part of General Science for the UPSC Exam. It is important not only from the science point of view but also because diseases and how to contain them are major topics in social issues and even polity/governance. This article tells you all about viruses for the IAS Exam.
This topic can also be related to various issues in Current Affairs. Furthermore, topics like Health, Disaster Management and Government Organisations related to Viruses and its consequences on the society can be expected as potential questions in the UPSC Exam or any other Government Exam. Aspirants preparing for such exams should be well aware of the topic in order to tackle such questions.
What is a Virus?
Viruses are non-cellular, microscopic infectious agents that can only replicate inside a host cell.
- From a biological perspective, viruses cannot be classified either as living organisms nor non-living.
- This is due to the fact that they possess certain defining characteristic features of living organisms and non-living entities.
- In a nutshell, a virus is a non-cellular, infectious entity made up of genetic material and protein that can invade and reproduce only within the living cells of bacteria, plants and animals.
- They are called non-cellular because they don’t have a cell structure, rather only the genetic material.
- Viruses are the border between living and nonliving organisms.
- They act as living organisms when they are present in a host organism (cell),
- Otherwise, they are nonliving organisms.
- They are crystal-like structures when they are outside, and becomes infecting and lethal when they enter a living cell.
- Viruses are inert outside a host cell, and then they are called virions.
- Some viruses partially contain DNA (DeoxyRibonucleic acid) or RNA (Ribonucleic acid) with single or double strands. It can get into the DNA of the host organism.
- Viruses are classified on the basis of genetic material – ds DNA (polio), dsRNA, ssDNA, ssRNA (orthomyxoviruses).
- Viruses cause diseases among animals and plants. Potato mosaic and tobacco mosaic are the common viral diseases among plants; chickenpox, AIDS and Ebola are the common viral animal diseases.
- Viroids and prions are the infecting proteins and RNA, they lack cell covers like a virus or any other eukaryotes. They were discovered by T Dienner in 1971 and these are also responsible for diseases among animals. E.g. mad cow disease.
Table: Some Diseases caused due to Viruses
|Some Diseases caused due to Viruses|
|Sr. No||Disease||Disease-Causing Virus||Transmission & Cause|
|1||AIDS||Human Immunodeficiency Virus (HIV)||Transmission: Exchange of Blood
Cause: Human & Primates
|2||Chicken Pox||Varicella Zoster Virus (VZV)||Transmission: Through Contact or Air
|3||Chikungunya||Chikungunya virus||Transmission: Aedes Mosquitoes
|4||Cold, influenza (flu) and most coughs||Rhino viruses||Transmission: AirBorne (Sneeze droplets)
|5||Dengue fever||Flavivirus||Transmission: Aedes Mosquitoes (Female)
|6||Ebola||Ebola virus||Transmission: Man to Animal Contact
Cause: Humans & Few Animals
|7||Foot and Mouth Disease||Picornavirus [genus Aphthovirus]||Transmission: Close-contact animal-to-animal spread
|8||Hepatitis B||Hepatitis B Virus (HBV)||Transmission: STD or Exchange of Blood
|9||Measles||Measles Virus||Transmission: AirBorne
|10||Polio or Poliomyelitis||Poliovirus||Transmission: Water Borne or Faecal to Mouth
|11||Smallpox||Variola major and Variola minor||Transmission: Through Air, Water or Contact
|12||Zika||Zika virus||Transmission: Aedes Mosquitoes
Cause: Humans & Primates
Coronaviruses are a large family of viruses that are common in various species of animals, such as cattle, camels, bats, and cats. They cause diseases ranging from cold to SARS.
- In some cases, animal coronaviruses can infect humans, which can then spread from person to person.
- This happened in the case of the SARS and MERS coronaviruses. It is also suggested that this might be happening in the current COVID-19 pandemic.
- Coronaviruses cause respiratory infections in humans which are generally mild, but sometimes, can be fatal.
- Coronaviruses are physically large as far as viruses go (26 – 32 kilobases), having a surface of spike projections (which resembles a crown and hence the name ‘corona’).
Watch and Learn – Coronavirus & Impact on Economy: RSTV – Big Picture
COVID – 19 and India’s Response
The Department of Science and Technology and the Science and Engineering Research Board (SERB) called for a Short-term Research Grant for Nano Coating COVID-19 in April 2020.
This rapid project was necessary for the emerging health care requirements in order to combat the COVID-19 Pandemic. The projects are discussed in the table below:
|Project 2, 3 and 4||
Click on the link to read more about Nano Mission launched by the Government of India.
Yara Virus Brazil
The virus has been named Yaravirus after ‘Yara’, a water-queen figure in Brazilian mythology.
Researchers have discovered an unusually small virus in a lake in Brazil.
The Yaravirus infects amoeba and has genes that have not been described before, something that could challenge how Deoxyribonucleic Acid (DNA) viruses are classified. The Yaravirus’ capsid doesn’t resemble any previously known protein. The Yaravirus does not infect human cells.
Watch and learn – Coronavirus & Digital Solutions: RSTV- Big Picture
Viruses UPSC Notes:- Download PDF Here
|Healthy States, Progressive India Report||Zoonotic Diseases|
|NCERT Books PDFs For UPSC||UPSC Books|
|UPSC 2020||Science and Technology Decoded for UPSC Exam|