Practice Questions

1. Define the term plant defence response.

A plant defence response is a feature or process that helps a plant prevent damage or infection by pathogens or herbivores.

2. Name two physical defence responses found in plants.

Any two of:

Waxy cuticle

Cellulose cell walls

Bark

Thorns

Hairs on leaves or stems

3. Explain how the waxy cuticle acts as a defence.

The waxy cuticle forms a waterproof barrier that prevents pathogens from entering the leaf surface.

4. Why are cellulose cell walls an effective defence against pathogens?

They are tough and difficult for pathogens to penetrate, helping to stop them entering plant cells.

5. Explain one way bark helps protect a plant.

Bark is made of dead cells that form a barrier and can fall off, removing pathogens attached to it.

6. Name two mechanical defences used by plants.

Thorns

Hairs
(Also acceptable: spines, curled leaves)

7. How do thorns reduce damage from herbivores?

They make the plant difficult or painful to eat, discouraging animals from feeding on it.

8. What is meant by a chemical defence in plants?

Chemical defences are substances produced by plants that kill pathogens or deter herbivores.

9. Some plants produce antibacterial chemicals. Why is this useful?

It prevents bacteria from growing and spreading, reducing the risk of infection.