Botany - Biological Classification Question with Solution | TestHub

In 1971, T.O. Diener discovered a new infectious agent that was smaller than viruses caused potato spindle tuber disease. In 1935, W.M. Stanley showed that viruses could be crystallized and those crystals consists of proteins. In 1892, Ivanowsky recognized certain microbes as casual organism of the mosaic disease of tobacco. M.W. Beijerinck demonstrated a fluid called Contagium vivum fluidum obtained from an infected tobacco plant can cause infection in other healthy plants.