Type the number

Exercise and reference answers

Questions

1. Answer

   1969

   Question

   Year Whittaker proposed five kingdoms

2. Answer

   1892

   Question

   Year Ivanowsky recognised the tobacco mosaic microbe

3. Answer

   1898

   Question

   Year Beijerinek described infectious living fluid

4. Answer

   1935

   Question

   Year Stanley crystallised viruses

5. Answer

   1971

   Question

   Year Diener discovered viroids

6. Answer

   5

   Question

   Kingdoms in Whittaker's system

Instructions

Type the number only.

Explanation