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 is a symbiotic association between 

  1. Algae and Fungi

  2. Algae and Roots of plants

  3. Fungi and Roots of plants

  4. Viruses and Bacteria
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Fungi present in the roots of the plants show a symbiotic relationship with each other. It helps the roots of the plants to absorb more nutrients and water from the soil. It also helps them obtain better resistance to environmental stresses. In return, plants provide shelter and nutrition to mycorrhiza.

So, option C is the correct answer.

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 relationships

  2. Ectoparasitism

  3. Endoparasitism

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

Mycorrhiza is a symbiotic relation seen between certain plants and fungi. The fungi live on the roots of certain plants and help them absorb water and nutrients from the soil in a better way. In return, plants provide shelter and nutrition to fungi. So, both the organisms mutually befit each other.

So this type of relationship is called symbiotic relationship.

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

Fungus which is found in Pinus root is

  1. Amanita

  2. Corticium

  3. Fornes

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

Mycorrhiza is the term used to define the association of fungi on roots of vascular plants. In the case of woody plants such as pine, birch and oak, the fungi belonging to the phyllum; Basidomycota and Acomycota form the mycorrhizal assoociations. Ectomycorrhizas, such as Amanita and Boletus form mycorrhizas on Pinus.

Thus, the correct answer is option A.

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

Mycorrhiza is an association between roots of higher plant and fungus. It is an example of

  1. Symbiosis

  2. Parasitism

  3. Helotism

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

Biologically, mycorrhiza is defined as an association of fungi and roots of vascular plants. In a mycorrhizal association, the fungus tends to colonise the host plant roots either intracellular or extracellular. However, this is a symbiotic association, which is generally mutualistic and rarely pathogenic.

Thus, the correct answer is option A.  

Multiple choice biology breeding and biotechnology method of plant breeding for crop improvement plant breeding for food production biotechnology

Which of the following is incorrectly matched?                         

  1. Disease - Black rot of crucifers; Causative Organism - Bacteria

  2. Disease - Brown rust of wheat; Causative Organism - Fungi

  3. Disease - Late blight of potato; Causative Organism - Virus

  4. Disease - Red rot of sugarcane; Causative Organism - Fungi
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Late blight of potato is caused by Phytophthora infestans a oomycetae (fungi). Cool climate and wet weather help infection and spread, responsible for the irish famines in the nineties.

So, the correct answer is 'Disease - Late blight of potato; Causative Organism - Virus'

Multiple choice biology breeding and biotechnology method of plant breeding for crop improvement plant breeding for food production biotechnology

The Ear cockier of wheat can be differentiated from Molya disease of wheat by the fact that in the former.

  1. Plants become dwarf, stem and leaves become twisted spike lets get distorted and grains get replaced by brown stony structures

  2. Plants become pale, leaves turn yellow with reddish lip, roots get matted and fail to ear

  3. Root tips swell and cyst adheres to roots that turn brown and fall

  4. Show hypertrophy of stern and leaves and roots swell
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ear cockle of wheat is caused by the nematode Anguina tritici, which causes the formation of galls (brown stony structures) in place of grains and distorts the spikelets.

Multiple choice biology breeding and biotechnology method of plant breeding for crop improvement plant breeding for food production biotechnology

Which pathogen causes the blast disease of rice?

  1. Cercospora personata

  2. Pyricularia oryzae

  3. Xanthomonas citri

  4. Tungro virus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Blast disease in rice is caused by the fungus Magnaporthe oryzae which was earlier known as Pyricularia oryzae. Different parts of the plants are affected by the fungus. The blast can occur wherever blast spores are present. Rice can have blast in all growth stages. There are lesions formed on the leaf, panicle and neck region of the plant. There is great loss in yield due to this disease affecting the rice plants.
Thus, the correct answer is option B.
Multiple choice economics environmental economics acid rain air pollution - effects and control air pollution and its effects

Mycorrhizal fungi, which form a mutualistic association with many plant roots, are particularly sensitive to the effects of acid rain. These fungi facilitate the absorption of water and nutrients by the plants; in turn, the plants provide sugars and amino acids without which the fungi could not survive.

The relationship between mycorrhizal fungi

  1. One partner benefits from the association and the other partner is harmed

  2. One partner benefits from the association and the other partner is neither harmed nor helped

  3. One partner preys upon the other partner

  4. Both partners benefit from the association

  5. Neither partner benefits from the association
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mycorrhizae are the symbiotic fungi that reside in roots of higher plants and increase soil fertility by nitrogen fixation and also increase water and mineral absorption by plant roots. Fungi are beneffited by this association as they get sugar and amino acids. Both partners are benefitted; association is symbiosis. 

Therefore, the correct answer is option D.