Plant diseases + defences

Question 1

what type of pathogens can plant diseases be caused by

Answer 1

• bacteria
• viruses
• fungi

Question 2

what organisms can plants diseases be caused by

Answer 2

• worms
• insects e.g. aphids

Question 3

what are 7 signs of plant diseases

Answer 3

• stunted growth
• spots on leaves
• area of decay (rot)
• abnormal growth e.g. galls, lumps
• malformed stems + leaves (curling)
• discolouration of leaves (yellow , black spots)
• presence of pests

Question 4

identification of plant diseases can be made by :

Answer 4

• reference to a gardening manual or website
• taking infected plants to a laboratory to identify the pathogen
• using testing hits that contain monoclonal antibodies

Question 5

what is a fungal disease in plants

Answer 5

Rose Black Spot

Question 6

what is a viral disease in plants

Answer 6

Tobacco Mosaic (TMV)

Question 7

what are the symptoms of rose black spot

Answer 7

• purple/ black spots on leaves
• yellow leaves + drop off
• Stunted growth –> rate of photosynthesis decreases

Question 8

how is rose black spot transmitted

Answer 8

• fungus thrives in wet + windy conditions
• through air or water
• direct contact by gardeners

Question 9

prevention of Rose black spot

Answer 9

• removing + destroying infected leaves –> otherwise fungus will spread

Question 10

treatment of rose black spot

Answer 10

fungicides

Question 11

symptoms of TMV

Answer 11

• small patches of light green, brown, yellow appear on leaves –> infects chloroplasts
• leaves smaller than usual:
  
  • affects rate of photosynthesis –> stunted growth

Question 12

how is TMV transmitted

Answer 12

contact between plants:
- naturally
- human contact