Question

question 1 (1 point)
which symptom is most commonly associated with a fungal infection like powdery mildew?
o a water-soaked lesions with oozing
o b white powdery growth on leaf surfaces
o c mosaic patterns and stunted growth
o d wilt and soft rot with foul odor

question 2 (1 point)
which of the following is a biotic cause of plant disease?
o a drought stress
o b nutrient deficiency
o c fungal infection
o d herbicide damage

question 3 (1 point)
a plant shows yellow mottling, stunted growth, and distorted leaves, but no mold, ooze, or rot. what is the most likely cause?
o a virus
o b nutrient deficiency
o c fungi
o d bacteria

Explanation:

• Question 1: Powdery mildew is a fungal disease. The key characteristic of powdery mildew is the presence of white powdery growth on leaf surfaces. Water - soaked lesions with oozing are more characteristic of bacterial infections. Mosaic patterns and stunted growth are often associated with viral infections. Wilt and soft rot with foul odor can be due to bacterial or some fungal (like soft - rot fungi) but not powdery mildew.
• Question 2: Biotic causes of plant diseases are living organisms. Fungal infection is a biotic cause as fungi are living organisms. Drought stress, nutrient deficiency, and herbicide damage are abiotic (non - living) causes.
• Question 3: Viral infections often cause yellow mottling, stunted growth, and distorted leaves without mold (which is fungal), ooze (which can be bacterial), or rot. Nutrient deficiency may cause yellowing but usually not in a mottled pattern with stunted growth and distorted leaves in the absence of other symptoms. Fungal infections may show mold. Bacterial infections may show ooze.

Answer:

• Question 1: B. White powdery growth on leaf surfaces
• Question 2: C. Fungal infection
• Question 3: A. Virus