Q.Mention two anti-herbivory defences seen in plants.

Predation — one organism killing and consuming another — does more than simply transfer energy between trophic levels; it performs two significant regulatory roles in a community. First, predators (and parasites) can serve as biological control agents, naturally suppressing the population of a pest species without recourse to chemical pesticides, since the predator's presence continuously checks the pest's numbers. Second, predation helps maintain species diversity: by preferentially targeting whichever prey species is currently most abundant, a predator prevents that species from monopolising resources and competitively excluding other prey species, thereby allowing multiple prey species to persist together in the same habitat rather than the strongest competitor driving the rest to local extinction. …