Plant Diseases

Question 1

How does magnesium deficiency affect the plant?

Answer 1

Plants cannot make enough chlorophyll. Leaves become yellow and growth slows down as plants cannot photosynthesis fully.

Question 2

How does nitrate deficiency affect the plant?

Answer 2

Protein growth will be limited so the growth of plants will be stunted. Plant will not produce a crop properly.

Question 3

Symptoms of plant diseases:

Answer 3

Stunted growth
Spots on leaves
Areas of decay rotting
Growths
Malformed stems and leaves
Discolouration
Pests e.g. aphids, caterpillars
Treated using pesticides or anti- fungal treatments

Question 4

How can plant diseases be identified?

Answer 4

Gardening manuals or online
DNA analysis/ laboratory tests
Testing kits (monoclonal antibodies)

Question 5

How do plants defend themselves?

Answer 5

Physical barriers:
- Cellulose strengthens plant cells, prevent entry of microorganisms
- Tough waxy cuticle on the surface of leaves acts as a barrier
- Layer of dead cells form protective layer

Chemical barriers:
- Produce antibacterial chemicals
- Poisons to deter herbivores

Mechanical Defences:
- Thorns and hairs
- Leaves that droop or curl when touched
- Mimicry to trick animals