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 biology useful and harmful microbes mycorrhiza classification of fungi harmful microorganisms

Sclerotia extract of .................. fungus produce a powerful hallucinogenic drug LSD and drug ergotine.

  1. Claviceps purpurea

  2. Aspergillus flavus

  3. Agaricus

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Claviceps purpurea is an ergot fungus that grows on the ears of rye and related cereal and forae plants. Consumption of grains or seeds contaminated with the survival structure of this fungus, the ergot sclerotium, can cause ergotism in humans and other mammals. Ergotine is a powerful astringent alkaloid extracted from ergot as a brown, amorphous, bitter substance. It produces hallucinating effect on humans. Thus, the correct answer is option A.

Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

Yeast like budding of Oidia in Mucor/ Rhizopus is called :

  1. Palmella

  2. Chantransia

  3. Torula

  4. Gongrosira
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
In liquid medium, rich in sugar and acidic pH, the hyphae of Rhizopus/Mucor produce small rounded oidia, which multiply by budding like yeast. This budding condition is called torula stage.
So, the correct answer is Torula'
Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

'Ergot' is obtained from

  1. Puccinia

  2. Rhizopus

  3. Claviceps

  4. Yeast
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Ergot are the alkaloids obtained from ergot fungi Claviceps purpurea which grow on rye plant. These fungi cause ergot of rye, a fungal disease in plants. The sclerotia of ergot fungi contain alkaloids which are used to produce LSD (Lysergic acid diethylamide) drugs that act on CNS (Central nervous system). They are natural hallucinogens and change mood, behaviour and thoughts like in psychosis, a condition in which thoughts and emotions are affected to such an extent that contact is lost with reality. 
So, the correct answer is 'Claviceps'.
Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

Mucor belongs to .......... sub-division of Eumycota.

  1. Mastigomycotina

  2. Ascomycotina

  3. Zygomycotina

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

Zygomycotina is composed of organisms that are characterized by the formation of ribbon-like aseptate hyphae and sexual reproduction with the formation of zygospores. The vast majority of human zygomycotic disease is caused by the members of the family Mucoraceae. This family includes zygomycetes that produce asexual sporangiospores in sporangia. Sporangium producers which may or may not produce stolons and rhizoids and included in the genera Mucor and Rhizomucor. Thus, the correct answer is option 'Zygomycotina'.  

Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

Ergot (of Rye) is obtained from

  1. Claviceps purpurea

  2. Puccinia graminis

  3. Alternaria solanii

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

Ergot of Rye is a plant disease that is caused by the fungus Claviceps purpurea. The so-called ergot that replaces the grain of the rye is a dark, purplish sclerotium.

Therefore A is correct option. 

Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

Claviceps purpurea is casual organism of 

  1. Smut of Barley

  2. Rust of Wheat

  3. Ergot of Rye

  4. Powdery Mildew of Pea
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Claviceps purpurea is the fungal pathogen causing ergot disease of rye. It infects rye grains, producing sclerotia containing toxic alkaloids. Smut (Ustilago), rust (Puccinia), and powdery mildew (various fungi) are different plant diseases.

Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

Which saprotroph is similar in appearance to the Mucor?

  1. Penicillium

  2. Neurospora

  3. Rhizopus

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

Mucor and Rhizopus are fungi belonging to the family Mucoraceae. Mucor is called as pin mould. Rhizopus is known as black mould. They are saprophytic fungi that grow on dead and decaying organic material. The fungal mycelium of Mucor and Rhizopus look like fine cottony threads on the surface of the bread. Thus the correct answer is option C.

Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

Fungus Rhizopus resembles moss in having _______.

  1. Hyphae

  2. Mycelium

  3. Spores

  4. Archegonia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Rhizopus is a fungus, therefore, non chlorophyllous. It has a saprophytic mode of nutrition. The organism is made of mycelium and produces spores for sexual reproduction.
Moss - Funaria is a Bryophyte, therefore, chlorophyllous, mode of nutrition being autotrophic (photosynthetic). It also produces spores as a result of sexual reproduction.
So, the correct answer is 'Spores'
Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

In Mucor, zygospore develops from :

  1. Promycelium

  2. Progametangium

  3. Gametangia

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

In mucor during sexual reproduction, compatible strains form short, specialized hyphae called gametangia. At the point where two complementary gametangia fuse, a thick-walled, spherical zygosporangium develops. The zygosporangium typically contains a single zygospore.

So the correct option is C.

Multiple choice biology kingdom monera, protista and fungi mycorrhiza classification of fungi useful and harmful microbes

Which of the following fungi consists chitosan in its cell wall?

  1. Penicillium

  2. Aspergillus

  3. Mucor

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

Mucor is a saprotrophic fungus. The cell wall of the fungus contains considerable amounts of chitosan. Chitosan is a linear polysaccharide composed of randomly distributed β-(1→4)linked D glucosamine and N-acetyl glucosamine. It has commercial application in agriculture, biopesticide, and winemaking. Thus the correct answer is option C.