Plant defences

Question 1

Physical plant defence

Answer 1

cellulose cell walls, make it harder for pathogens to enter
tough waxy cuticles act as an additional barrier.
Trees have thick bark for extra protection, and when it falls off the pathogens go with it, the same idea works for plants with a lot of dead cells on the stem. 

Question 2

Chemical plant defence

Answer 2

many plants produce microbial chemicals that protect them from pathogens
some plants produce poisons to deter herbivores from eating them

Question 3

Mechanical plant defence

Answer 3

Plants with hairs and thorns deter animals from eating or laying eggs on them
Mimicry is used to trick animals making leaves look unappealing
Leaves that droop when touched can scare animals away and dislodge insects.