Researched
Viruses discovered
Sap from sick tobacco plants still infected healthy plants after filtering, revealing agents smaller than any bacterium: viruses.
Open in the interactive tree →Dmitri Ivanovsky (1892) and Martinus Beijerinck (1898) found that the tobacco mosaic agent passed through filters that hold back bacteria. Wendell Stanley crystallised the tobacco mosaic virus in 1935, and electron microscopes first showed viruses in the late 1930s.
Prerequisites
- Microscope1665
- Germ theory1861
Unlocks
- DNA is the hereditary molecule1944Hershey and Chase used a bacterial virus to show that DNA carries heredity
- Reverse transcriptase1970
- Oncogenes1976