Biology Paper 1, 4.3.3 Plant disease (biology only)

State 6 things that you can detect plant disease in plant. [3 marks]

• stunted growth.

• spots on leaves.

• areas of decay

• growth

• discolouration.

• malformed stems

Suggest 3 ways to identify plant disease. [3 marks]

• Use garden website.

• Take infected plants to lab to identify pathogens.

• Use testing kits that contain monoclonal antibodies.

Explain the effect of the lack of nitrate ions for plants. [2 marks]

• Stunted growth.

• (Because) not enough protein for growth.

Explain the effect of the lack of magnesium ions for plants. [2 marks]

• Chlorosis.

• (Because) not enough magnesium ions to make chlorophyll.

State 3 physical response to resist invasion of microorganisms in plants. [3 marks]

• Cellulose cell walls.

• Waxy culture.

• Layer of dead cell which fall off.

State 2 chemical response to resist invasion of microorganisms in plants. [2 marks]

• Antibacterial chemicals.

• Poisons to deter herbivores.

State 3 mechanical response to resist invasion of microorganisms in plants. [3 marks]

• Hair deter animals.

• Mimicry to trick animals.

• Leaves which droop or curl when touched.