4.1.1 Plant Defences Against Disease

Question 1

Plants detect infection by…

Answer 1

Detecting foreign chemicals produced by the pathogen, and the nucleus starts a chain of defence

Question 2

Physical defences?

Answer 2

Production of callose and lignin

Question 3

What do physical defences do (c + l)?

Answer 3

Callose: blocks plasmodesmata, sticks to cell walls to prevent pathogen from entering
Lignin: prevents further entry of the pathogen

Question 4

Chemical defences?

Answer 4

Chemicals can be produced in the cells that travel through the phloem and alert other cells; antibacterial / anti fungal chemicals that can destroy the pathogen / counteract toxins