Biology

Microbes and Plant Diseases

1,118 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

Northern corn leaf blight is caused by

  1. Puccinia sorghi

  2. Bipolaris maydis

  3. Exserohilum turcicum

  4. Puccinia polysora

  5. Cercospora zeae-maydis
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Correct answer. Northern corn leaf blight is caused by the fungus Exserohilum turcicum.

Multiple choice

White mold of pepper is caused by

  1. Botrytis cinerea

  2. Sclerotinia sclerotiorum

  3. Peronospora tabacina

  4. Stemphylium solani

  5. Macrophomina phaseolina
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Correct answer. White mold of pepper is caused by Sclerotinia sclerotiorum.

Multiple choice

Identify the mismatched pair of disease and its causative agent.

  1. Black root rot of cotton : Thielaviopsis basicola

  2. Black rot of crucifers : Xanthomonas campestris

  3. Gray mold of hemp : Agrobacterium tumefaciens

  4. Downy mildew of mustard : Peronospora parasitica

  5. Bottom rot of lettuce : Rhizoctonia solani
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Correct answer. The most important disease of hemp is gray mold, caused by the fungus Botrytis cinerea. Crown gall of hemp is caused by Agrobacterium tumefaciens.

Multiple choice

Which disease of wheat is caused by a virus?

  1. False eyespot of wheat

  2. Wheat yellow leaf

  3. Pink seed of wheat

  4. Downy mildew of wheat

  5. Ergot of wheat
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Correct answer. Wheat yellow leaf virus is a wheat, barley, rye, and oat pathogenic virus of the family Closteroviridae. The virus proliferates in the phloem of its host plants, interfering with the plant's ability to produce sufficient chlorophyll (chlorosis), causing the leaves to yellow and the plant to die.

Multiple choice

Which of the following pairs of 'crop disease : causative agent' is not correctly matched?

  1. Coffee leaf rust : Hemileia vastatrix

  2. Ergot of rye : Claviceps purpurea

  3. Early blight of potato : Phytophthora infestans

  4. Crown rust of oats : Puccinia coronata

  5. Halo blight of beans : Pseudomonas syringae
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Correct answer. Early blight of potato caused by the fungus Alternaria solani. Phytophthora infestans is an oomycete that causes the serious potato disease known as late blight of potato.

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. Symptoms of wildfire of tobacco include yellowish green spots on leaves. It causes losses in seedlings and field plants and occurs worldwide.