Biology plant diseases Flashcards
Tobacco mosaic virus.
A virus that affects many species of plants.
Causes a mosaic pattern on leaves - parts of the leaves become discoloured.
Discolouration means the plant can’t carry out photosynthesis so effects growth.
Viral disease.
Causes a mosaic pattern on leaves - parts of the leaves become discoloured.
Tobacco mosaic virus.
Rose black spot.
Fungus that causes purple or black spots.
Leaves turn yellow and drop off.
Less photosynthesis so less growth.
Spreads by wind or water.
Can be treated with fungicides or by removing the affected leaves and destroying them.
Fungus that causes purple or black spots.
Leaves turn yellow and drop off.
Rose black spot.
What are nitrates used for in plants.
Needed to make proteins for growth - lack of nitrates can cause stunted growth.
What are magnesium ions used for in plants.
needed for making chlorophyll - lack causes plants to suffer from, chlorosis and have yellow leaves.
Ways to identify a plant has a disease.
Stunted growth. Spots on the leaves. Patches of decay (rot). Abnormal growths (lumps). Malformed stems or leaves. Discolouration.
Way to identify a plant disease.
Gardening manual/ website.
Taking infected plants to a laboratory so scientists can identify the pathogen.
Using testing kits to identify the pathogen using monoclonal antibodies.
Physical Plant defences.
Leaves and stems have a waxy cuticle barrier to pathogens.
Cell walls another physical barrier
Bark - a layer of dead cells around the stems another barrier.
Chemical defences
Some can produce antibacterial chemicals.
Some produce poisons.
Mechanical defences
Some plants have thorns and hairs (stop animals from touching and eating them).
Some plants have leaves that drop or curl. (to knock insects of their leaves.)
Some mimic other organisms - passion flower has bright yellow spots that too like butterfly eggs to stop other butterflies laying their eggs on it.
