Flashcards · Biology · Plant Defences and Disease
Physical Defences of Plants
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What is the leaf cuticle?
A waxy layer on the outside of the epidermis.
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How does the cuticle protect a leaf from pathogens?
It is waterproof and tough, so water and pathogens cannot easily get in.
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What is the cell wall made of?
Cellulose.
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How does the cell wall protect the plant?
It is rigid and strong, and difficult for pathogens to break through.
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How can a plant strengthen its cell wall when attacked?
By laying down extra material at the point of infection.
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What is bark?
A layer of dead cells that protects the trunk and branches.
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Give an example of a plant with thorns.
Rose, hawthorn or cactus.
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What do hairs on leaves do?
They deter insects and grazing animals.
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What is mimicry in plants?
Looking like something unappetising, such as the passion flower that mimics butterfly eggs.
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Why can stomata be a weak point?
Pathogens can enter the leaf through them.
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What do guard cells do?
Open and close the stomata.
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How do plants protect their stomata from bacteria?
They close them when they detect bacteria.
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Why does the cuticle make it harder for fungal spores?
They need water to germinate, and the waxy surface stays dry.
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What is a pest?
An organism that damages a plant.
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Why can plants not rely only on physical barriers?
Pathogens can still enter through stomata or wounds.
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What is the common mistake about the cuticle?
Saying it is made of cellulose. It is made of wax.