View source for Plant Defences Against Micro-Organism

==Key Stage 4==
===Meaning===
'''Plant defences against micro-organisms''' are the methods [[plant]]s have to reduce the chance of infection and fight [[disease]] causing [[pathogen]]s.

===About Plant defences against micro-organisms===
: '''Plant defences against micro-organisms''' can be grouped into two main categories: Physical Barriers and Chemical Barriers.
====Physical Barriers====
*Waxy Cuticle - [[Leaf|Leaves]] have a waxy cuticle which can prevent [[micro-organism]]s from entering the [[leaf]].
*Bark - A layer of dead cells surrounds the outside of a tree trunk which blocks [[micro-organism]]s form getting into the stem.
*Cell Walls - The [[Cell Wall|cell walls]] of individual [[Cell (Biology)|cells]] can act as a barrier to [[virus]]es entering the [[Cell (Biology)|cells]].

====Chemical Barriers====
: [[Plant]]s produce a number of [[chemical]]s which have [[antiseptic]] or [[antibiotic]] properties.
: When [[plant]]s become distressed they give off pheromones which cause nearby [[plant]]s to also produce [[antiseptic]] and [[antibiotic]] [[chemical]]s, preventing [[pathogen]]s from spreading.