What was the contribution of the scientist $D$.$J$. Ivanowsky $(1892)$?

$A$: Viruses are considered as a link between living and non-living organisms.
$R$: Viruses behave as inert,non-living particles in a free state,while they exhibit active,living behavior inside a host cell.

Which of the following serves as an indicator of atmospheric pollution?

What type of virus is the Tobacco Mosaic Virus $(TMV)$?

Which of the following is an important characteristic of viruses?

Lichen is usually cited as an example of 'symbiosis' in plants where an algal and a fungal species live together for their mutual benefit. Which of the following will happen if algal and fungal partners are separated from each other?
$A$. Both will survive and grow normally and independent from each other.
$B$. Both will die.
$C$. Algal component will survive while the fungal component will die.
$D$. Fungal component will survive while algal partner will die.
Based on your answer,how do you justify this association as symbiosis?