Plant defences

Question 1

what is a physical defence mechanism in a plant

Answer 1

Something physically preventing the entry of pathogens Eg tree bark , waxy cuticle , cellulose - cell walls

Question 2

what is a chemical defence mechanism in a plant

Answer 2

Chemicals the plant can secrete , these could be poisonous , antimicrobial

Question 3

what is a mechanical defence mechanism in a plant

Answer 3

Similar to physical but these serve a greater purpose than physical EG Thorns stop a plant from eating or touching the plant or even Mimicary

Question 4

What are magnesium ions needed for

Answer 4

To produce chlorophyll - symptoms - chlorosis (discoloured leaves )

Question 5

What are nitrate ions needed for

Answer 5

Nitrate ions are needed for protein synthesis , symptoms - stunted growth

Question 6

What are symptoms of all plant diseases and how are they treated

Answer 6

stunted growth, spots on leaves ,areas of decay (rot) ,malformed stems or leaves ,discolouration ,the presence of pests.
Identification can be made by:
reference to a gardening manual or website
taking infected plants to a laboratory to identify the pathogen
using testing kits that contain monoclonal antibodies.

Question 7

Give examples of plant diseases

Answer 7

tobacco mosaic virus as a viral disease
black spot as a fungal disease
aphids as insects.