3.3 Plant disease Flashcards
Completed | T3 Infection and Response | physicsandmathstutor
1
Q
How do aphids cause damage to plants? (2)
A
- They use their sharp mouthparts to extract sap from the plant phloem, weakening the plant.
- They are vectors who can transfer pathogens from diseased plants to healthy plants.
2
Q
How can we reduce the number of aphids?
A
- Chemical pesticides.
- Biological pest control - using ladybirds.
3
Q
Why do plants need a good supply of nitrate ions? (2)
A
- Required for the conversions of sugars into proteins which plants need to grow.
- Inadequate (poor) supply of nitrate ions results in the plant experiencing growth stunts.
4
Q
Why do plants need a good supply of magnesium ions? (2)
A
- Required to synthesise chlorophyll, which absorbs light energy during photosynthesis.
- Inadequate (poor) supply of magnesium ions results in the leaves not being able to photosynthesise properly so they turn yellow (chlorosis).
5
Q
What are the symptoms of disease in plants? (7)
A
- Stunted growth (lack of nitrate ions).
- Spotted leaves (eg. rose black spot fungus).
- Decay/rotting.
- Growths.
- Malformation of stems/leaves.
- Discolouration.
- Presence of pests.
6
Q
What are the ways plant disease can be identified? (3)
A
- Reference to a gardening website or manual.
- Laboratory testing.
- Monoclonal antibody test kits.
7
Q
What are examples of physical defence responses used by plants? (4)
A
- Cellulose cell walls.
- Tough waxy cuticle on leaves.
- Outside layer on stems/bark on trees.
- Leaf fall.
8
Q
What are examples of chemical defence responses used by plants? (2)
A
- Antibacterial chemicals.
- Poisons.
9
Q
What are examples of mechanical defence responses used by plants?
A
- Thorns and hairs to deter animals
- Leaves that droop/curl on contact
- Mimicry to trick animals
