Plant diseases and defences

Question 1

What are nitrates needed for in plants?

Answer 1

To make proteins and therefore for growth.

Question 2

What are magnesium ions needed for in plants?

Answer 2

Making chlorophyll which is needed for photosynthesis.

Question 3

What are some signs that a plant has a disease?

Answer 3

Stunted growth
Discolouration
Patches of decay

Question 4

How can different plant diseases be identified?

Answer 4

By taking the infected plant to a lab
Looking at signs in a gardening manual
Using testing kits

Question 5

What are some physical defences of plants?

Answer 5

Plants have a cellulose cell wall which makes it hard for pathogens to penetrate.
Most plants have a waxy cuticle which provides a barrier to stop pathogens from entering.

Question 6

What are some chemical defences of plants?

Answer 6

Some plants release antibacterial chemicals which kill bacteria.
Some plants release poisons to deter herbivores.

Question 7

What are some mechanical defences of plants?

Answer 7

Some plants have thorns to stop animals touching and eating them.
Some plants mimic other organisms to prevent themselves from being eaten.