Plant Pathology Mock Exam

Which is a necrotic symptom?

• Wilting

• Tumor formation

• Rotting of fruit

• Dwarfing

Witches’ broom is an example of:

• Necrotic symptom

• Hyperplastic symptom

• Hypoplastic symptom

• Pre-necrotic symptom

Koch’s Postulates are used to:

• Identify causal pathogens

• Differentiate viruses from bacteria

• Induce plant resistance

• Diagnose nutrient deficiencies

A symptom complex refers to:

• A single visible symptom

• Combination of multiple symptoms

• Presence of pathogen signs

• A microscopic observation only

Which of the following is an example of a sign?

• Root gall

• Leaf spot

• Sclerotium

• Chlorosis

Diseases caused by unfavorable physical factors are:

• Infectious

• Non-infectious

• Saprophytic

• Obligate

Blackheart of potato is caused by:

• Lightning

• Oxygen deficiency

• Sunscald

• Freezing injury

Etiolation results from:

• Excessive water

• Excess light

• Deficiency of light

• Strong winds

Chilling injury in tropical plants is caused by exposure to:

• >40 °C

• 0–10 °C

• -20 °C

• >50 °C

Which air pollutant is also a natural plant hormone at proper concentrations?

• Nitrogen oxides

• Ozone

• Ethylene

• PANs