Question

Contagium vivum fluidum was proposed by
A. D.J. Ivanowsky
B. M. W. Beijerinck
C. Stanley
D. Robert Hooke

Answer 1

Hint:-Contagium vivum fluidum is a term that was first used to depict a virus. Dutch microbiologist and botanist, Martinus Willem Beijerinck, one of the founders of virology, while studying tobacco mosaic virus, proposed that the tobacco mosaic virus (TMV) can pass through the finest filter available at that time.

Complete Answer:-
Martinus Willem Beijerinck was one of the founders of the new era of virology. In 1898, while studying the causative agents tobacco mosaic virus disease observed that even after filtering the sample through the smallest pores (which was available then), the liquid filtrate could infect its host. Hence he concluded that the causative agent was fluid or non-particulate and coined the phrase “Contagium vivum fluidum”.

Russian botanist Dmitri Ivanovsky, who was also studying the cause of tobacco mosaic disease found out, in 1892, that the causative agent of the disease can pass through the smallest filter available then which was known as Chamberlain's porcelain filter. But he was unsure whether the filtrate obtaining contamination was due to crack in the filter or not. Later Martinus Willem Beijerinck established his notion independently following this experiment. In 1935, after the discovery of the electron microscope, American biochemist and virologist Wendell Meredith Stanley showed the first image of the virus. English scientist Robert Hooke was the first scientist to visualize microorganism under a microscope.

So the correct answer is option “B” - M. W. Beijerinck.

Note:- Dmitri Ivanovsky, was the first person to discover the fluid nature of the causative agent of tobacco mosaic disease which was later termed as a virus. The findings were left to M. W. Beijerinck who independently studied the nature of this contaminant following Ivanovsky’s path, using the filter which restricts even the smallest bacteria to pass through it and established the theory of “Contagium vivum fluidum”.