Viruses are The Main Cause of Many Diseases

Viruses are The Main Cause of Many Diseases

Get some knowledge about Virus's life, shape and the diseases caused by it.

A virus is an infectious particle consisting only of the viral genes enclosed in a shell made up of proteins. It can replicate itself  only inside the living cells of other organisms. Viruses can infect all types of organisms from big organisms of plants and animals microorganisms like bacteria etc. The infectious complete body of virus is called virion. Each virion is composed of nucleic acid and capsid. Therefore, virus is generally called nucleocapsid.

Most viruses have these parts:-

1: Viral Genome ---> It is a single linear or circular molecule of nucleic acid.

2: Capsids/Coats ---> The protein shell that encloses genome is called capsid.

3: Envelope ---> Some viruses have an outer envelope. These are the accessory structures that cover the capsids.

 

Viruses show wide variety of sizes. Generally, viruses are extremely small. They are much smaller than bacteria. Most viruses have the diameter between 20 to 300 nanometers. Most viruses cannot be seen with optical/compound microscope. So, electron microscope is used to see them.

All the viruses are belonged to Phylum Vira. It has two sub-phyla:

1: Sub-Phylum Deoxyvira ---> This sub-phylum includes DNA core viruses.

2: Sub-Phylum Ribovira ---> These viruses contain RNA core.

Retroviruses are the special type of RNA viruses which can convert their single stranded RNA into double stranded DNA. These viruses have special enzyme called reverse transcriptase. This enzyme is responsible for the conversion of RNA into DNA.

Viruses causes different diseases in animals and plants. Viral diseases of Animals are:-

1: AIDS (Acquired Immuno Deficiency Syndrome). It is caused by HIV virus.

2: Cancer ---> This is caused by tumor virus.

3: Hepatitis ---> Inflamation of liver.

4: Polio ---> This is caused by Polio virus.

5: Influenza and cold ---> These diseases are caused by influenza and cold viruses.

6: Small Pox ---> This disease is caused by pox virus.

7: Mumps and Measels ---> These diseases are caused by mumps and measels viruses.

8: Herpes Simplex ---> This disease is caused by Herpes virus.

Viruses diseases of Plants are:-

1: TMV (Tobacco Mosaic Virus)

2: Mosaic virus of Cocumber and Lettuce

3: Yellow disease of Potato

4: Tomato bunchy top disease

5: Cotton Leaf curl disease

6: Necrotic diseases

7: Tumours