Induced defenses in plants are typically activated in response to damage and result in what?

• A. Mechanical changes in plant tissues that deter insects.
• B. Chemical changes in plant tissues triggered by damage that deter insects.
• C. Constitutive physical barriers present regardless of damage.
• D. Attracting pollinators to compensate for damage.

Answer: (B)

Induced defenses are plant responses that kick in after tissue damage or herbivore attack. When damage occurs, plants activate signaling networks that turn on defense genes, leading to the production of chemicals in the tissues. These chemical changes deter insects by making the plant less palatable or more toxic, through compounds like protease inhibitors, tannins, alkaloids, glucosinolates, and other secondary metabolites, and sometimes by emitting volatiles that recruit predators or parasites of the herbivores. This is why the correct answer highlights chemical changes in plant tissues triggered by damage that deter insects. Constitutive physical barriers are present regardless of damage, and attracting pollinators is not a defensive chemical response, while some mechanical responses can occur, the hallmark of induced defenses is the chemical defense produced after damage.