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

In citrus, aerolate leaf spot is caused by

  1. Altemaria altemata

  2. Altemaria tenuis

  3. Aspergillus flavus

  4. Rhizoctonia solani

  5. Aspergillus niger
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Aerolate leaf spot in citrus is caused by Rhizoctonia solani.

Multiple choice

Match the apple diseases in List - A with causing fungal pathogens in List - B and select the correct answer using the codes given below the lists.

 
List - A
List - B
A. Cotton root rot 1. Gymnosporangium clavipes
B. Coral spot 2. Phymatotrichum omnivorum
C. Silver leaf 3. Chondrostereum purpureum
D. Quince rust 4. Gymnosporangium yamadae
5. Tubercularia vulgaris

  1. A - 2, B - 4, C - 3, D - 5

  2. A - 1, B - 2, C - 3, D - 1

  3. A - 2, B - 5, C - 3, D - 1

  4. A - 4, B - 5, C - 1, D - 2

  5. A - 1, B - 2, C - 5, D - 4
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In apple, cotton root rot disease is caused by Phymatotrichum omnivorum, coral spot is caused by Tubercularia vulgaris, silver leaf disease is caused by Chondrostereum purpureum and quince rust disease is caused by Gymnosporangium clavipes. Hence, the sequence of codes A - 2, B - 5, C - 3, D - 1 is correct.

Multiple choice

Which of the following diseases are caused by fungal pathogens only in barley?

P. Kernel blight Q. Anthracnose R. Dwarf bunt S. Leaf rust T. Basal glume rot

  1. Only P and Q

  2. Only Q and R

  3. Only R and S

  4. P, R and T

  5. Q, R and S
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Kernel blight disease is caused by bacteria Pseudomonas syringae pv. syringae and basal glume rot is caused by bacteria Pseudomonas syringae pv. atrofaciens. Anthracnose, dwarf bunt and leaf rust are caused by fungal pathogens Collectotrichum cereale, Tilletia controversa and Puccinia hordei, respectively.

Multiple choice

Which of the following diseases is/are caused by Burkholderia glumae in Oryza glaberrima?

P. Sheath brown rot Q. Grain rot R. Foot rot

  1. Only P

  2. Only Q

  3. Only R

  4. Both P and Q

  5. Both Q and R
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Grain rot is a bacterial disease caused by Burkholderia glumae and symptoms of this disease appear on seedlings and spikelets. Seedlings raised in boxes turn brown and rot. The glumes (lemma) of infected spikelets are discoloured. Initially dirty gray, they turn yellow-brown, then become dark brown and shrunken, ultimately dry. In mild infections, only the palea discolour. Brown bands can be seen distinctly over the belly of the infected kernel.

Multiple choice

Match the rice diseases in Group - I with the causing microbes in Group - II.

 
Group - I
Group - II
P. Black kernel rot 1. Gaeumannomyces graminis
Q. Leaf scald 2. Lasiodiplodia theobromae
R. Crown sheath rot 3. Drechslera gigantea
S. Eyespot 4. Rhynchosporium oryzae

  1. P - 2, Q - 4, R - 1, S - 3

  2. P - 2, Q - 1, R - 4, S - 3

  3. P - 3, Q - 4, R - 1, S - 2

  4. P - 4, Q - 1, R - 2, S - 3

  5. P - 3, Q - 4, R - 2, S - 1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The fungus Lasiodiplodia theobromae causes black kernel rot disease in maize, leaf scald disease is caused by Rhynchosporium oryzae in rice, crown sheath rot disease is caused by Gaeumannomyces graminis and eyespot disease is caused by Drechslera gigantea. Hence, the correct answer using the codes is P - 2, Q - 4, R - 1, S - 3.

Multiple choice

The class of fungi containing 5 orders and 21 families is

  1. Agaricostilbomycetes

  2. Atractiellomycetes

  3. Classiculomycetes

  4. Cystobasidiomycetes

  5. Pucciniomycetes
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The Pucciniomycetes (formerly known as the Urediniomycetes) are a class of fungi in the Pucciniomycotina subdivision of the Basidiomycota. The class contains 5 orders, 21 families, 190 genera and 8016 species. It includes several important plant pathogens causing forms of fungal rust.

Multiple choice

The fungus most commonly used in the cuisines and medicines of China is

  1. Tremella mesenterica

  2. Tremella fuciformis

  3. Tremella foliacea

  4. Pseudohydnum gelatinosum

  5. Myxarium nucleatum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Tremella fuciformis is a species of fungus. It produces white, frond-like, gelatinous basidiocarps (fruiting bodies). It is widespread, especially in the tropics, where it can be found on the dead branches of broadleaf trees. This fungus is commercially cultivated and is one of the most popular fungi in the cuisines and medicines of China.

Multiple choice

Which of the following fungi is a well known worldwide insect parasite?

  1. Fusarium

  2. Saksenaea vasiformis

  3. Aspergillus fumigatus

  4. Rhizopus oryzae

  5. Beauveria bassiana
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This fungi is usually isolated as a saprophytic contaminant. Worldwide, known as an insect parasite. Sympodial development of single-celled conidia on a narrow geniculate or zig-zag rachis emanating from a flask-shaped conidiophore.

Multiple choice

Basidia are specialised end-cells on which the fungi that possess them produce their spores. Which of the following fungi is characterised by their unique tuning fork basidia?

  1. Morchella

  2. Ergot

  3. Calocera cornea

  4. Cloud ear fungus

  5. Dibotryon morbosum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Calocera cornea is a jelly fungus that grows on decaying wood. It is a member of the Dacrymycetales, an order of fungi characterised by their unique "tuning fork" basidia.