Biology

Microbes and Plant Diseases

1,145 Questions

Microbes and plant diseases examine the role of fungi, bacteria, and viruses in causing infections in plants and humans. Topics cover symbiotic associations like mycorrhiza, fungal structures, and specific agricultural pathogens. Practice these biology questions to master microbiology concepts for upcoming competitive examinations.

Fungal associationsPlant pathogensMicrobial structuresBacterial infections

Microbes and Plant Diseases Questions

Multiple choice

The plant disease which is caused by a bacteria is

  1. corn smut

  2. citrus canker

  3. wheat leaf rust

  4. red rot of sugarcane

  5. potato late blight
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Citrus canker is a disease affecting citrus species that is caused by the bacterium Xanthomonas axonopodis.

Multiple choice

Blast disease of rice is caused by

  1. Alternaria solani

  2. Entyloma oryzae

  3. Piricularia oryzae

  4. Helminthosporium oryzae
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Blast disease of rice is caused by the fungus Pyricularia oryzae (also called Magnaporthe oryzae), which is one of the most devastating rice pathogens. Alternaria solani affects potatoes/tomatoes, Entyloma oryzae causes smut disease, and Helminthosporium oryzae causes brown spot but not blast.

Multiple choice

Wildfire of tobacco is caused by

  1. Agrobacterium rhizogenes

  2. Erwinia carotovora

  3. Pseudomonas syringae

  4. Ralstonia solanacearum

  5. Rhodococcus fascians
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Wildfire of tobacco is caused by Pseudomonas syringae, a rod-shaped, gram-negative bacterium with polar flagella. 

Multiple choice

Identify the incorrect matching of plant disease and causative microorganism.

  1. Rapeseed stem canker: Leptosphaeria maculans

  2. Citrus canker: Xanthomonas axonopodis

  3. Apple canker: Neonectria galligena

  4. Grape canker: Eutypa lata

  5. Mulberry canker: Fusarium pini
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Mulberry canker is caused by the fungus Gibberella baccata. Pine pitch canker is caused by the fungus Fusarium pini.

Multiple choice

Identify the incorrect matching.

  1. Angular leaf spot: Xanthomonas campestris

  2. Bacterial wilt: Erwinia tracheiphila

  3. Downy mildew: Pseudoperonospora cubensis

  4. Alternaria leaf blight: Alternaria cucumerina

  5. Crown and foot rot: Fusarium solani
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Angular leaf spot in cucurbits is caused by Pseudomonas amygdali.

Multiple choice

Charcoal rot is caused by

  1. Erysiphe cichoracearum

  2. Macrophomina phaseolina

  3. Pythium ultimum

  4. Glomerella glycines

  5. Alternaria alternata
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Macrophomina phaseolina is a Botryosphaeriaceae fungus.

Multiple choice

Brown blight in tea is caused by

  1. Cylindrocladium lanceolatum and Exobasidium vexans

  2. Cylindrocladium lanceolatum and Glomerella cingulata

  3. Exobasidium vexans and Glomerella cingulata

  4. Glomerella cingulata and Colletotrichum gloeosporioides

  5. Colletotrichum gloeosporioides and Cylindrocladium lanceolatum
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Brown blight in tea is caused by Glomerella cingulata and Colletotrichum gloeosporioides.

Multiple choice

Which of the following is a pair of viral diseases of cereals?

  1. Black point and common bunt

  2. Barley yellow dwarf and common bunt

  3. Barley yellow dwarf and high plains disease

  4. High plains disease and common bunt

  5. Black point and barley yellow dwarf
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Barley yellow dwarf is a plant disease caused by the barley yellow dwarf virus.

Multiple choice

Common root rot is a disease of wheat caused by

  1. Colletotrichum coccodes and Marssonina salicicola

  2. Fusarium culmorum and Fusarium graminearum

  3. Tilletia tritici and Tilletia laevis

  4. Tapesia yallundae and Tapesia acuformis

  5. Cochliobolus sativus and Claviceps purpurea
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Common root rot is a disease of wheat caused by one or more fungi. 

Multiple choice

Apple scab is caused by

  1. Sclerotinia fruticola

  2. Uncinula necator

  3. Venturia inequalis

  4. Erysiphe polygoni
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 Apple scab is caused by Venturia inequalis.The disease manifests as dull black or grey-brown lesions on the surface of tree leaves, buds or fruits.