B5 Plant Diseases + Physical Defences

Question 1

How can plant diseases be detected?

Answer 1

They can be detected by stunted growth; dark spots of leaves; area of decay and rot; malformed stems and leaves; discolouration and the presence of pests

Question 2

How can you identify which disease the plant has?

Answer 2

Reference to a gardening manual or website, or taking infected plants to labs to identify the pathogen

Question 3

Need to know knowledge

Answer 3

Tobacco mosaic virus as a virus
Black spots as a fungi
Aphids as an insect

Question 4

Knowledge of ions

Answer 4

Nitrate ions for protein synthesis and therefore growth, and magnesium ions needed to make chlorophyll

Question 5

How do physical responses work?

Answer 5

They’re responsible for resisting incasion by having a range of defences e.g tough waxy cuticle on leaves

Question 6

Chemical plant defences

Answer 6

Antibiotics, chemicals, or poison to deter herbivores