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 botany living world mycorrhiza classification of fungi kingdom monera, protista and fungi useful and harmful microbes

Mycorrhiza, a relationship between fungi and roots of higher plants is

  1. Parasitic relationship

  2. Saprophytic relationship

  3. Symbiotic relationship

  4. Epiphytic relationship
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mycorrhiza is a symbiotic association between Fungi and roots of higher plants, which grow in mineral deficient soil. It helps to absorb water and minerals like phosphorous from soil for the benefit of plant and in turn gets nutrition from the plant, as fungi cannot synthesize its own food.

So, the correct answer is option C.

Multiple choice botany living world mycorrhiza classification of fungi kingdom monera, protista and fungi useful and harmful microbes

A symbiotic association between fungus and underground part of a plant is

  1. Hyperparasite

  2. Mycorrhiza

  3. Endophyte

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

A. Hyperparasite is an organism which lives off another parasite.

B. Mycorrhiza is the symbiotic relationship between vascular plant root and fungi. Its name comes from "myco" means fungi and "rhiza" means roots. Fungi come into direct contact with plant roots and with soil, adding to the plant's ability to gather nutrients and water from the soil through the fungus.
C. Endophyte is a bacterium or fungus which lives inside the plant for at least a part of its life cycle.
D. subterranean parasite is a parasite which lives underground on roots etc 
So, the correct answer is 'Mycorrhiza'.

Multiple choice botany living world mycorrhiza classification of fungi kingdom monera, protista and fungi useful and harmful microbes

In what way does a fungus growing around the roots of higher plants benefit them?

  1. It products antimicrobial substances

  2. It produces growth promoting substances

  3. It helps in absorbing water nitrogen and other minerals

  4. All of them
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The associations between roots and fungi are called mycorrhizae. The roots provide essential nutrients for the growth of the fungi. In return, the large mass of fungal hyphae acts as a virtual root system for the plants, increasing the amount of water and nutrients that the plant may obtain from the surrounding soil. So, the correct option is "D" (All of them)
Multiple choice botany living world mycorrhiza classification of fungi kingdom monera, protista and fungi useful and harmful microbes

The symbiotic association between fungi and roots of higher plants is referred to as:

  1. lichen

  2. mycorrhiza

  3. biofertiliser

  4. biocontrol agent
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The symbiotic association between fungi and roots of higher plants is referred to as mycorrhiza.
  • The plant supports the fungus by providing carbohydrates needed for fungal growth, while the fungus helps the plant by increasing its root surface area.
  • So, the correct answer is 'Mycorrhiza'.
Multiple choice botany living world mycorrhiza classification of fungi kingdom monera, protista and fungi useful and harmful microbes

Which one of the following is a useful functional association between fungi and the roots of higher plants?

  1. Lichen

  2. Coralloid root

  3. Biofertilizer

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

Mycorrhiza is a useful functional association between fungi and the roots of higher plants in which fungi absorb nutrients from the soil as their roots are not such strong and the tree provides food to the fungi. The best example is Orchid mycorrhiza

So the correct option is 'Mycorrhiza'

Multiple choice botany living world mycorrhiza classification of fungi kingdom monera, protista and fungi useful and harmful microbes

VAM (Vesicular-arbuscular mycorrhizae) represents

  1. Saprophytic bacteria

  2. Symbiotic fungi

  3. Saprophytic fungi

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

Mycorrhiza biofertilizer is also known as VAM, adheres to plants rhizoids leading to development of hyphae. Hyphae boost development and spreading of white root in to soil leading to significant increase in rhizosphere. These hyphae further penetrate and form arbuscules within the root cortical. VAM fungi form a special symbiotic relationship with roots of plant that can enhance growth and survivability of colonized plants. Mycorrhiza biofertilizer is very useful in organic farming as well as normal commercial farming. So, VAM is a symbiotic fungi and not a parasitic algae, saprophytic bacteria and saprophytic fungi. Thus, the correct answer is option B.

Multiple choice botany living world mycorrhiza classification of fungi kingdom monera, protista and fungi useful and harmful microbes

The association between fungus and root system of certain plants is called as

  1. Amensalism

  2. Competition

  3. Mycorrhiza

  4. Cauliflory
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Mycorrhiza is a symbiotic association between a fungus and a plant.
  •  The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, its root system.
  •  Mycorrhizae play a role in plant nutrition, soil biology and soil chemistry.
  • Hence, Mycorrhiza is the association between fungus and root system of some plants
  • So, the correct answer is 'Mycorrhiza'.
Multiple choice botany living world mycorrhiza classification of fungi kingdom monera, protista and fungi useful and harmful microbes

Mycorrhiza is an example of

  1. Symbiotic relationship

  2. Ectoparasitism

  3. Endopasitism

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

Symbiosis describes close interactions between two or more different species in which both species benefit. A mycorrhiza is defined as a symbiotic relationship between the roots of vascular plants and fungi.

Multiple choice botany living world mycorrhiza classification of fungi kingdom monera, protista and fungi useful and harmful microbes

What is true about mycorrhiza?

  1. It is an association of fungus and higher plants.

  2. It is association of algae and fungi.

  3. It is association of algae with higher plants.

  4. None of the above.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mycorrhizas are symbiotic associations essential for one or both partners, between a fungus (specialised for life in soils and plants) and a root (or other substrate-contacting organ) of a living plant, that is primarily responsible for nutrient transfer. Mycorrhizas occur in a specialised plant organ where intimate contact results from synchronised plant-fungus development. Mycorrhizal fungi are a major component of the soil microflora in many ecosystems, but usually have limited saprophytic abilities. They are considered to have many important roles in natural and managed ecosystems.

Thus, the correct answer is option A.