Viruses are known as:

They are pollution indicators and never grow in polluted areas.

Assertion $A$: Lichens are symbiotic associations between algal and fungal components. Reason $R$: The mycobiont components of fungi are heterotrophic. Which option is correct for Assertion $A$ and Reason $R$?

What was the contribution of the scientist $M. W. Beijerinck$ in $1898$ regarding the study of viruses?

Who discovered viroids?

Prions are primarily composed of ...... .