Question

Select the wrong statement
A. Mosaic disease in tobacco and AIDS in human being are caused by viruses
B. The viroids were discovered by D.J. Ivanowski.
C. W.M. Stanley showed that viruses could be crystallized.
D. The term Contagium vivum fluidum was coined by M.W. Beijerinck.

Answer 1

Hint: Virus and viroids both are parasites which can only see under the microscope. Virus infects all types of living organisms and causes various diseases while viroids only infect plants. They replicate their genetic material inside other organisms or called that host.

Complete Answer:
- Viruses contain nucleic acid as mostly RNA sometimes DNA and a protein coat while Viroids contain only RNA and do not have protein coat.
- Viruses produce protein when they replicate. On the other hand, viroids do not produce protein.
- Mosaic disease in tobacco and AIDS in human beings are the virus disease caused by Tobacco mosaic virus and HIV respectively.
- Viroids first discovered by Theodor Otto Diener (1971). The first virus discovered was the Potato spindle tuber viroid which causes disease in potato.
- ON the other hand D.J. Ivanowski discovered the virus.
- W.M Stanley gives the information about virus crystallization.
- M.W. Beijerinck coined The term Contagium vivum fluidum .

So, the correct answer is the viroids were discovered by D.J. Ivanowski.
Note: Viroids are smaller in the size from viruses. Hepatitis B, AIDS, Tobacco, and Influenza are the diseases caused by the viruses and potato spindle tubular is the plant disease caused by viroids.