What evidence led Stanley to the conclusion that viruses are not alive?
(a) He was able to isolate crystals of tobacco mosaic virus. (b) Tobacco mosaic virus is composed of proteins and RNA. (c) Tobacco mosaic virus reproduces inside plant cells.
(d) The virus causes a disease in tobacco plants.
All living things have to have the ability to reproduce on their own; however, viruses depend on other organisms to reproduce, showing that they are not living things.
