Mild grazing of plants by herbivores:

The interaction between two living organisms of different species which is beneficial to both but is not obligatory because they can live without each other is known as

Which one of the following is not a matching pair of certain organism$(s)$ and the kind of association?

$A$: An ecological niche is usually occupied by a single species.
$R$: More than one species can live in the same habitat.

Which of the following plants develops various structures for protection against herbivores?

Explain the general information about population interaction and show the various outcomes observed between them.