WorksheetsPlant Pathology Mock Exam
Total questions: 25
Worksheet time: 12mins
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
Ozone injury results in:
Bronzing of lower leaf surfaces
Water-soaked spots and flecks along veins
Leaf malformation and stunting
Etiolation
Excess phosphorus deficiency causes:
Erect leaves with purplish tint
Stunted root growth with necrosis
Leaf bronzing
White streaks on leaves
Sunscald in fruits occurs due to:
Freezing
Too much sunlight
Low oxygen
Ethylene exposure
Air pollutants such as dusts and soot cause:
Scorching
Necrosis and leaf fall
Blight
Chlorosis
Abiotic diseases differ from biotic diseases because:
They are transmissible
They are caused by living organisms
They are non-transmissible
They always show identical symptoms
Plant pathogenic bacteria are generally:
Gram-positive, spore-forming
Gram-negative, non-spore-forming
Gram-positive, flagellated
Gram-negative, obligate parasites
The main means of bacterial reproduction is:
Budding
Binary fission
Sporulation
Conjugation
Crown gall disease is caused by:
Pseudomonas solanacearum
Agrobacterium tumefaciens
Streptomyces scabies
Xanthomonas campestris
Soft rot of vegetables is caused by:
Pectobacterium carotovorum
Ralstonia solanacearum
Xanthomonas oryzae
Erwinia chrysanthemi
Fastidious vascular bacteria are restricted to:
Xylem or phloem
Root hairs only
Cuticle layer
Epidermis
Citrus greening (HLB) is caused by:
Xylella fastidiosa
Candidatus Liberibacter spp.
Pectobacterium carotovorum
Agrobacterium tumefaciens
Pierce’s disease of grape is associated with:
Xanthomonas
Xylella fastidiosa
Clavibacter michiganensis
Pantoea stewartii
Which of the following is NOT a symptom caused by bacteria?
Blight
Canker
Wilt
Mosaic
A common sign of bacterial infection is:
Rust pustules
Sclerotia
Bacterial ooze
Mycelial growth
Ratoon stunting disease of sugarcane is caused by:
Leifsonia xyli
Erwinia chrysanthemi
Streptomyces scabies
Xanthomonas vesicatoria
