Plant Diseases and Defences

Question 1

Give a way, other than TMV and rose black spot, that plants can become diseased through living things.

Answer 1

Aphids, which feed on the sap of a plant from its phloem, destroying a plant.
Common ways to get rid of aphids are using ladybugs to get rid of aphids as they eat them.

Question 2

What is a nitrate deficiency?

Answer 2

Lack of nitrate ions, which are needed for photosynthesis, can lead to stunted growth of a plant.

Question 3

What is chlorosis (magnesium deficiency)?

Answer 3

Lack of magnesium ions, which are needed to make chlorophyll, can lead to a lack of chlorophyll and therefore discolouration of the plants leaves and a lack of photosynthesis and therefore, growth.

Question 4

Give 4 signs/symptoms of plant disease.

Answer 4

Stunted growth
Spots on leaves
Areas of decay
Malformed stems or leaves
Discolouration
The presence of pests

Question 5

How could you identify a plant disease?

Answer 5

Using testing kits that contain monoclonal antibodies
Taking infected plants to a lab to identify the pathogen
Looking them up in garden manual or on a website

Question 6

Give three physical defence responses of plants.

Answer 6

Cellulose cell walls
Tough waxy cuticle on leaves
Layers of dead cells around stems

Question 7

Give two chemical plant defence responses.

Answer 7

Antibacterial chemicals

Poisons to deter herbivores

Question 8

Give three mechanical adaptations of plants.

Answer 8

Thorns and hairs deter animals
Leaves which droop or curl when touched
Mimicry to trick animals