Plant defense responses

Question 1

Physical responses

Answer 1

All plant cells have a cellulose cell wall which is difficult for microorganisms such as bacteria to penetrate
Leaves are covered with a thin ily layer called the waxy cuticle making it difficult for microorganisms to penetrate which protects the plant from attack
Bark is a barrier to entry by microorganisms, as bark ages, it eventually falls off and is replaced with fresh bark underneath

Question 2

Chemical response

Answer 2

Plants can release antibacterial chemicals which kill bacteria and prevent them attacking the plant
Plants can release poisons to deter herbivores from grazing on the plant

Question 3

Mechanical defense system

Answer 3

Sharp thorns directly protect a plant from being eaten by a herbivore
Other plants have hairs which irritate the mouth of herbivores making the plant difficult to eat
Sometimes we find plants which have special leaves which droop or curl when touched
This might scare herbivores as they are not used to plants moving like this
Mimicry, some plants imitate the look of nettles when they have no sting to prevent herbivores from eating them