Plant Disease And Defences Flashcards
What do plants need to stay healthy
Mineral ions
Nitrates
Magnesium ions
Why do plants need mineral ions
To prevent them from suffering deficiency symptoms
Why do plants need nitrates
To make proteins and grow
Otherwise they will have a stunted growth
Why do plants need magnesium ions
To make chlorophyll which is needed for photosynthesis
Otherwise they will suffer from Chlorosis and yellow leaves
How can plants get diseases
By being infected by viral Bacterial or fungal pathogens
By being infested and damaged by insects like aphids
What are the common signs that a plant has a disease
Stunted growth Spots on the leaves Patches of decay Abnormal growths Malformed stems or leaves Discolouration
What are plants physical defences
Wait cuticle acts as barrier to stop pathogens entering
Plant cells have cell walls that act as a secondary barrier to pathogens
Layers of dead cells around stem which also act as a barrier
What are plants chemical defences
Producing antibacterial chemicals which kill bacteria like mint plant and witch hazel
Produce poisons which deter herbivores like tobacco plants
What are plants mechanical defences
Thorns and hairs to prevent animals
Leaves droop or curl when something touches it - knock insects off
Mimicing other organisms and tricks them to not eat them
