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

What is the term used to describe the degree of severity of a plant disease?

  1. Pathogenicity

  2. Virulence

  3. Resistance

  4. Disease severity

  5. Disease incidence
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Disease severity refers to the degree of damage or loss caused by a plant disease, including the extent of tissue damage, yield reduction, or economic impact.

Multiple choice

What is the main disease that affects cotton crops in the Western Zone?

  1. Fusarium wilt

  2. Verticillium wilt

  3. Alternaria leaf spot

  4. Bacterial blight
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fusarium wilt is the main disease that affects cotton crops in the Western Zone, causing wilting and yellowing of leaves, leading to reduced yields.

Multiple choice

What is the causal agent of late blight disease in potatoes?

  1. Phytophthora infestans

  2. Alternaria solani

  3. Fusarium oxysporum

  4. Rhizoctonia solani
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Late blight disease in potatoes is caused by the oomycete Phytophthora infestans, which affects the leaves, stems, and tubers of the plant.

Multiple choice

Which of the following is a fungal disease that affects wheat crops?

  1. Rust

  2. Smut

  3. Powdery mildew

  4. Leaf spot
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rust is a common fungal disease that affects wheat crops, causing yellow or brown spots on the leaves and stems of the plant.

Multiple choice

What is the vector of citrus tristeza virus, a disease that affects citrus trees?

  1. Aphids

  2. Whiteflies

  3. Thrips

  4. Mites
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Citrus tristeza virus is transmitted by aphids, which feed on the sap of citrus trees and spread the virus to healthy plants.

Multiple choice

Which of the following is a bacterial disease that affects tomato plants?

  1. Bacterial wilt

  2. Bacterial spot

  3. Canker

  4. Blossom end rot
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bacterial wilt is a bacterial disease that affects tomato plants, causing the leaves to wilt and die.

Multiple choice

What is the causal agent of powdery mildew, a disease that affects a wide range of plants?

  1. Erysiphe cichoracearum

  2. Podosphaera leucotricha

  3. Sphaerotheca pannosa

  4. Uncinula necator
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Powdery mildew is caused by a group of fungi belonging to the genus Erysiphe, with Erysiphe cichoracearum being a common species that affects a wide range of plants.

Multiple choice

What is the causal agent of downy mildew, a disease that affects grapes?

  1. Plasmopara viticola

  2. Peronospora destructor

  3. Phytophthora infestans

  4. Pseudoperonospora cubensis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Downy mildew in grapes is caused by the oomycete Plasmopara viticola, which affects the leaves and fruit of the plant.

Multiple choice

Which of the following is a disease that affects sugarcane crops?

  1. Red rot

  2. Smut

  3. Ratoon stunting disease

  4. Yellow leaf disease
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Red rot is a fungal disease that affects sugarcane crops, causing a reddish-brown discoloration of the stalks and reducing the sugar content.

Multiple choice

What is the causal agent of black rot, a disease that affects crucifers?

  1. Xanthomonas campestris pv. campestris

  2. Erwinia carotovora subsp. carotovora

  3. Pseudomonas syringae pv. tomato

  4. Alternaria brassicae
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Black rot in crucifers is caused by the bacterium Xanthomonas campestris pv. campestris, which affects the leaves, stems, and pods of the plant.

Multiple choice

Which of the following is a disease that affects mango trees?

  1. Powdery mildew

  2. Anthracnose

  3. Bacterial wilt

  4. Leaf spot
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Anthracnose is a fungal disease that affects mango trees, causing dark spots on the leaves, fruits, and twigs of the tree.

Multiple choice

Which disease is known to cause wilting and yellowing of tomato plants, leading to reduced fruit production?

  1. Bacterial wilt

  2. Fusarium wilt

  3. Verticillium wilt

  4. Powdery mildew
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Fusarium wilt is a fungal disease that affects tomato plants, causing wilting and yellowing of leaves, eventually leading to reduced fruit production. It is a common and destructive disease in tomato cultivation.

Multiple choice

Which of the following is a characteristic feature of fungal cell walls?

  1. Cellulose

  2. Chitin

  3. Peptidoglycan

  4. Lignin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Chitin is a unique polysaccharide found in the cell walls of fungi, providing structural support and protection.

Multiple choice

Which fungal structure is responsible for producing spores?

  1. Hyphae

  2. Mycelium

  3. Spores

  4. Basidia
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Basidia are specialized structures in certain fungi where spore production takes place.

Multiple choice

What is the term for the vegetative part of a fungus?

  1. Hyphae

  2. Mycelium

  3. Spores

  4. Conidia
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mycelium is the vegetative part of a fungus, consisting of a network of hyphae.