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

Hyphomycete is a type of fungus. Which of the following hyphomycetes either live their life-cycles in the bodies of dead nematodes or trap and kill nematodes in order to supplement their nitrogen requirements?

  1. Arthrobotrys

  2. Gibberella

  3. Angulimaya

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

Species of the hyphomycete genus (Arthrobotrys) produce constricting loops that quickly shut to grab nematodes or non-constricting loops or hyphal networks that entangle nematodes or sticky knobs that adhere to nematodes as they swim by.

Multiple choice

Recently, genome of Laccaria Bicolor (an ectomycorrhizal fungi) was sequenced. Which of the following kinds of relationship does it form with plants?

  1. Neutralism

  2. Mutualism

  3. Commensalism

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

The relationship between Laccaria Bicolor and plants can be described as mutualism. Laccaria Bicolor shows an excess of enzymes used in ammonia uptake and a lack of enzymes that would be needed to degrade plant wall material. Thus, the fungus provides nitrogen and does not cause any harm to the trees in return for glucose, which it gets from photosynthetic plants. 

Multiple choice

Dieback disease of citrus is caused by

  1. virus

  2. fungus

  3. bacterium

  4. Cu-deficiency
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Dieback disease in citrus is a well-documented physiological disorder caused specifically by a deficiency of copper (Cu) in the soil.

Multiple choice

The fungal partner in lichens is often called

  1. mycobiont

  2. phycobiont

  3. isidia

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

Lichens are plant like organisms, under a microscope the association is seen to consist of millions of cells of algae (called the phycobiont) woven into a matrix formed of the filaments of the fungus (called the mycobiont).

Multiple choice

Which fungus is responsible for the oropharyngeal thrush?

  1. Cryptococcus

  2. Histoplasma

  3. Amaranths

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

Oropharyngeal thrush, or oral candidiasis, is a fungal infection caused by the overgrowth of Candida species, most commonly Candida albicans. Cryptococcus and Histoplasma are different types of fungi that typically cause systemic or respiratory infections.

Multiple choice

Which of the following features is similar in both monerans and fungi?

  1. Structure of fruiting body

  2. Absorptive heterotrophy

  3. Cellular structure

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

Absorptive heterotrophy is similar in both monerans and fungi.In this an organism secretes enzymes externally into its environment to digest organic materials which are then absorbed.

Multiple choice

The cell wall of fungi is made up of

  1. chitin

  2. cellulose

  3. peptin

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

The cell wall of fungi is made up of chitin.The structure of chitin is comparable to the polysaccharide cellulose, forming crystalline nanofibrils .