Question

The concept of "Contagium vivum fluidum" was given by

• A. D. J. Ivanowsky
• B. W. M. Stanley
• C. M.W. Beijerinek
• D. R. H. Whittaker

Answer 1

The Correct Option is C

The concept of "Contagium vivum fluidum" (meaning "contagious living fluid") was proposed to describe the nature of the infectious agent causing tobacco mosaic disease, based on early observations about its properties.

Let's examine the contributions of the scientists listed in the context of the discovery of viruses:  

• D. J. Ivanowsky (1892): He was a Russian botanist who demonstrated that the agent causing tobacco mosaic disease was filterable. He showed that the sap from infected plants remained infectious even after passing through Chamberland filters, which were known to retain bacteria. This suggested the agent was smaller than bacteria or possibly a toxin.
• W. M. Stanley (1935): An American biochemist who succeeded in crystallizing the Tobacco Mosaic Virus (TMV). His work showed that this infectious agent had properties of both chemicals (crystallizable) and living organisms (able to replicate and cause disease). He shared the Nobel Prize in Chemistry in 1946 for this work.
• M.W. Beijerinek (1898): A Dutch microbiologist who independently confirmed Ivanowsky's filtration experiments. Importantly, he showed that the infectious agent could diffuse through an agar gel (unlike bacteria) and that it could only multiply within living, dividing host cells. Based on these findings – its filterability, fluid-like diffusion, and requirement for living tissue to multiply – he concluded it was not a conventional microbe or toxin but a distinct entity he called "Contagium vivum fluidum".
• R. H. Whittaker (1969): An American ecologist known for proposing the five-kingdom system of biological classification (Monera, Protista, Fungi, Plantae, Animalia). His work was in the field of taxonomy and ecology, not directly related to the initial discovery of viruses.

Therefore, the scientist who proposed the concept and coined the term "Contagium vivum fluidum" was M.W. Beijerinek.

Answer 2

The concept of "Contagium vivum fluidum" was given by M.W. Beijerinck. He coined this term in 1898 to describe the infectious agent of tobacco mosaic disease, which he discovered was caused by a virus. Beijerinck hypothesized that the disease was caused by a "living, contagious fluid," which we now understand as a virus.

• D.J. Ivanowsky is credited with discovering the tobacco mosaic virus, but it was Beijerinck who coined the term "Contagium vivum fluidum."
• W.M. Stanley later crystallized the virus and helped confirm that it was a virus.
• R.H. Whittaker is known for his contributions to the five-kingdom classification of life, not related to viruses.

Thus, correct answer is (C) : M.W. Beijerinek.