viruses

Virus The term virus was coined by Pasture. For the discovery of viruses’ first-time work was performed by a scientist Iwanowsky, who was discovered TMV (tobacco mosaic virus). it was later crystallized by a scientist Stanley. Now another scientist Beijuinuk called ‘viruses as “Contagium Vivum Fluidum”. What that mean? Living infectious fluid. As today we know viruses are passed in ...

The viruses important questions for papers and tests are as follow What are virus and virion? Ans: Viruses are infectious particles consisting only of the viral genes enclosed in a shell made up of proteins. The infectious complete body of viruses is called virion. Virion is composed of nucleic acid and capsid. Therefore, viruses are generally called nucleocapsid. What are ...

Virus or viral diseases does not produce symptoms directly in the animals (humans). But it indirectly affects the host. Virus causes different diseases in animal and plants. Some virus stimulates the lysosome of host cell to produce hydrolytic enzymes. These enzymes cause bursting of host cell. These hydrolytic enzymes damage other cells. Sometimes, envelope of the virus is toxic to the ...

Classification of Viruses is to name and place the virus into different groups or subgroups in phylum Vira. The viruses are placed or classified into a group or sub-phylum on the basis of their different characteristics (Phenotypic Characteristics). Those characteristics are as follow: Phenotypic Characters of Viruses 1. Type of nucleic acid (DNA or RNA) they have. 2. Morphology of ...

The tobacco mosaic disease is caused by a rod-shaped virus called as TMV. TMV stands for Tobacco Mosaic Virus. It causes disease in Tobacco plant. It is a single stranded RNA virus with rod shape as you can see in following picture. Structure & Features of Tobacco Mosaic Virus (TMV) It is about 300 nm long and 15 nm in diameter ...

Bacteriophage are viruses that infect bacteria. They were discovered independently by Frederick W. Twort in England in 1915 and by Felix d’ Herelle at the Pasteur’s Institute in Paris in 1917. The term bacteriophage age was coined by D’ Herelle which means bacteria eater. Bacterial viruses are widely distributed in nature. Phages exist in almost all bacteria. Systematic:    Position Division: ...

Virus can be defined as non-cellular infectious entities which contain RNA or DNA encased in protein coat and reproduce only in living cell. History of Discovery of Virus The word VIRUS is derived from latin word venome means poisonous substance, was used to describe any disease-causing substance. About 50 years before development of the electron microscope, the existence of viruses ...