Plant Defence Responses:

Plants defend themselves from pathogens and pests using 3 types of defence mechanisms:

1. PHYSICAL DEFENCES:

CELLULOSE CELL WALLS: provide a structural BARRIER against pathogens.

WAXY CUTICLE: on leaves act as a BARRIER to prevent the entry of pathogens.

LAYERS OF DEAD CELLS: (like bark on trees) act as a BARRIER to pathogens and pests.

2. CHEMICAL DEFENCES:

ANTIBACTERIAL CHEMICALS: produced by plants to KILL BACTERIA.

POISONS: to deter herbivores from eating the plants.

3. MECHANICAL ADAPTATIONS:

THORNS AND HAIRS: deter animals from touching or consuming the plant.

LEAVES THAT DROOP OR CURL: when touched, protecting them from being eaten by knocking insects off.

MIMICRY: to trick animals into avoiding the plant.