Question

Select the mismatched pair.
A. M. Stanley- Viruses could be crystallised
B. D.J. Iwanowsky- Coined the term virus
C. B.J. Beijerinck- extract of the infected plants of tobacco caused infection in healthy plants
D. None of these

Answer 1

Hint: The name virus originated from the Latin word that means slimy liquid or poison. It was initially used to describe any infectious agent, along with the agent of tobacco mosaic disease, tobacco mosaic virus. In the early years of discovery, viruses were referred to as filterable agents.

Complete answer:
A) W.M. Stanley crystallised Tobacco Mosaic Virus (TMV) for the very first time. Hence, the option (A) is not mismatched
B) D.J Iwanowsky recognized certain microbes as causal organisms of the mosaic disease of the tobacco. The term ‘virus’ was coined by Louis Pasteur and not Iwanowsky. Hence, this option is mismatched.
C) M.W. Beijerinck demonstrated that the extract of the infected plants of tobacco could cause infection in healthy plants and called this fluid as “Contagium vivum fluidum” i.e., infectious living fluid. Hence, this option is not mismatched.

So, the correct option is (B) as it is the mismatched pair.

A virus is a small parasite that is not able to reproduce on its own. Once it infects a vulnerable cell, it can easily replicate and produce more of its kind. A virus can order the cell machinery to produce more viruses. Most viruses have either RNA or DNA as their genetic material. The nucleic acid may be single- or double-stranded. The entire infectious virus particle is called a virion which consists of the nucleic acid and an outer shell of protein. The simplest viruses contain only enough RNA or DNA to encode four proteins. The most complex can encode 100 – 200 proteins.

Note:
Since many viruses can infect a large number of different cell types, genetically modified viruses often are used to carry foreign DNA into a cell. This approach provides the basis for a growing list of experimental gene therapy treatments. There is an extensive use of viruses in cell biology research and their potential as therapeutic agents.