3.2 Plant defence responses

Physical defence responses

* Cellulose cell walls.
* Tough waxy cuticle on leaves.
* Layers of dead cells around stems (bark on trees) which fall off.

Chemical plant defence responses.

* Antibacterial chemicals
* Poisons to deter herbivores.

Mechanical adaptations

* Thorns and hairs deter animals.
* Leaves which droop or curl when touched.
* Mimicry to trick animals.

how do physical defences prevent infections

create a barrier to resist microorganisms