Which of the following are most suitable indicators of $SO_2$ pollution in the environment?

Assertion $(A)$: The capsid of a virus is made up of many small subunits called capsomeres.
Reason $(R)$: Viruses exhibit active and living behavior in a virus-free state.

Assertion $(A)$: The pathogen responsible for Parkinson's disease in humans is viroids.
Reason $(R)$: Viroids are smaller in size than viruses.

Which of the following structures is involved in the sexual reproduction of lichens?

Which structure do lichens use for sexual reproduction?

Satellite $RNAs$ are present in some