Question

question 4 (1 point)
what distinguishes a biotic plant disease from an abiotic one?
o a it can be reversed with proper watering
o b it results from poor soil ph alone.
o c it only affects leaves, not stems.
o d it is caused by a living microorganism infecting plant tissue.

question 5 (1 point)
which type of pathogen produces spores that spread via wind, water, or animals and often causes powdery coatings on plants?
o a fungi
o b bacteria
o c viruses
o d nematodes

question 6 (1 point)
which set of symptoms is most indicative of a viral infection in plants?
o a soft rot with a foul smell
o b mosaic patterns and leaf distortion
o c wilting due to vascular blockage
o d powdery fungal growth on leaves

Explanation:

Question 4

• Biotic plant diseases are caused by living organisms (like fungi, bacteria, viruses). Abiotic are due to non - living factors (e.g., poor soil pH, improper watering).
• Option a: Reversing with watering is abiotic (e.g., drought stress).
• Option b: Poor soil pH alone is abiotic.
• Option c: Biotic can affect stems (e.g., stem canker).
• Option d: Correct as biotic is caused by living microorganisms.

• Fungi produce spores (e.g., powdery mildew fungi have spores that spread via wind etc. and cause powdery coatings).
• Bacteria: Usually spread by water, insects but don't typically form powdery coatings from spores in this way.
• Viruses: Spread by vectors (e.g., insects) but don't produce spores.
• Nematodes: Are worms, don't produce spores for this kind of spread.

• Option a: Soft rot with foul smell is often bacterial (e.g., bacterial soft rot).
• Option b: Mosaic patterns and leaf distortion are classic viral symptoms (e.g., tobacco mosaic virus).
• Option c: Wilting due to vascular blockage can be bacterial (e.g., bacterial wilt) or fungal (e.g., Fusarium wilt).
• Option d: Powdery fungal growth is fungal (e.g., powdery mildew).

Answer:

d. It is caused by a living microorganism infecting plant tissue.

Question 5