SB5g-h Flashcards
What are the physical barriers for plants?
- Cuticle (thick waxy waterproof layer that covers surface of leaves)
- Thick layer of bark
What are 2 ways pathogens can overcome a plant’s physical barrier?
- Using enzymes to hydrolyse the walls of the plant to enter
- Finding other parts of the plant with weaker cell walls
What are the chemical barriers for plants?
- Poisons
- Insect repellents
How do plants use their chemical barriers?
They produce chemical substances that are toxic to pests so once the pest bites the plant they get poisoned.
What is the medicine and source of medicine for malaria?
Artemisinin - found in Wormwood plants
What is the medicine and source of medicine for pain/fever?
Salicylic acid (aspirin) - found in Willow trees and Meadowsweet trees
What is another use for plants?
Used in production of medicine to treat diseases.
How are medicines made free from contamination in labs?
Usage of aseptic techniques ensures the destruction of any pathogens that can contaminate the medicines.
How are medicines sterilised in labs?
Autoclave.
How do farmers check for diseased crops?
Drones.
How do plants get infected?
- Fungal disease spread by spores
- Pests and pathogens in the soil
What are some problems that plants could have?
- Lack of water/ too much water
- Lack of nutrients in the soil
- Pests
- Diseases
What are some symptoms of plant diseases?
- Changes in growth
- Changes in colour of leaves
- Blotching in leaves
- Lesions on stem and leaves
What are 2 ways of identifying problems in plants?
- Distribution analysis - checking the environment of crops (flooding, droughts, lack of nutrients, pests, pathogens)
- Diagnosis - soil and plant samples are sent to labs to test and determine cause of problem
How is plant diagnosis done?
- Pathogens are taken from the plant and grown in agars to check their DNA and identify them
- They check the soil for lack of nutrients and toxins
