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 mineral nutrition in plants deficiency diseases and symptoms deficiency symptoms macronutrients and micronutrients

You observed that a plant's younger leaves, not the older ones, are yellowing. You recall that the cause of plant sickness can be diagnosed by which leaves are yellowing.
What is the most likely cause of your plant's blight?

  1. Too much shade

  2. Lack of nitrogen-fixing Rhizobium bacteria

  3. A deficiency in a mobile mineral nutrient.

  4. A deficiency in a non-mobile mineral nutrient.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

If there is a deficiency of mobile nutrients, the symptoms are first seen in the leaves. Mobile and immobile nutrients refer to the transportability of these (K), (Mg), (Cl), (Zn) and (Mo).

So, the correct option is 'A deficiency in a non-mobile mineral nutrient'.

Multiple choice botany indian botanical gardens and herbarium importance of herbarium taxonomic aids taxonomy and systematic botany botanical gardens in india

The common fungicide used in preventing growth of fungus on herbarium specimens is 

  1. Copper sulphate

  2. Lime

  3. Mercuric chloride

  4. Both A and B
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The common fungicide used in preventing growth of fungus on herbarium specimens is mercuric chloride. It is highly toxic compound that volatilizes slightly at ordinary temperature and appreciably at 100 degrees Celsius. Mercuric chloride is corrosive to mucous membranes and used as a topical antiseptic and disinfectant. 

So, the correct option is 'Mercuric chloride'.

Multiple choice zoology asexual reproduction sporulation reproduction in bacteria asexual reproduction in organisms

Penicillium produces

  1. Zoospores

  2. Mitospores

  3. Meiospores

  4. Both B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The species of penicillium multiply by vegetative fragmentation as well as asexual and sexual methods.

Asexual reproduction begins with the formation of asexual motile spores called conidia, which are born on the erect, aerial hyphae called conidiophores. The conidiophores branch multiple times and finally terminate into cylindrical bodies called sterigma. At the time of conidium formation, the nucleus of sterigma divides by mitotic division into two. The terminal portion of sterigma gets separated with one nucleus and is called conidium. When it is fully grown another conidium is formed below the first conidium in succession at the end of sterigma. The spores thus formed are mitospores, which germinate to form genetically identical saprophyte.
In sexual reproduction, the spores or conidium are formed by meiosis from the diploid parent zygote. Ascogonium, a female sex organ and Antheridium, a male sex organ arise on adjacent branches and fuse to form meiospores.
Zoospores are spores with flagella. They are motile spores. They are not produced by Penicillium.
Thus, the correct answer is option D.

Multiple choice botany economic importance of bacteria and fungi fungi: benefits and harmful effects useful and harmful fungi uses of fungi

If all fungi in an environment that perform decomposition were to suddenly die, then which group of organisms should benefit most, due to the fact that their fungal competitors have been removed?

  1. Plants

  2. Protists

  3. Prokaryotes

  4. Animals
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Prokaryotics will be the next group after fungus that will benefit if all the fungus were to die a sudden death.
  • As the protist group consist of mostly disease causing organisms and plants are one that take the benefit from the decomposed material while animals are the those that feed on organisms from first and second tropic level.
  • Prokaryotes mostly have single celled organisms such as bacteria which help in decomposition of the organic waste left by the higher organisms
  • So, the correct answer is 'Prokaryotes'.
Multiple choice biology aids to health antibiotics and their uses common health care methods immunization, treatment and antibiotics first aid

The fungus contaminant of Staphylococcus culture of Fleming was

  1. Aspergillus flavus

  2. Claviceps purpurea

  3. Penicillium notatum

  4. Penicillium chrysogenum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Alexander Fleming was working on a Bacterial culture of Staphylococcus to studying the action of lysozyme and its role in the fighting of the infection.
  • While he was working with the culture he noticed that the bacterial culture's growth is inhibited due to the growth of fungal infection on it.
  • The fungus that infected the culture was  Penicillium notatum , whose secretion was later to be discovered as antibiotic penicillin.
  • So the answer Penicillium notatum is correct.
Multiple choice botany plant breeding plant breeding for disease resistance and insect resistance method of plant breeding for crop improvement plant breeding for food production

Hairy leaves of many plants are associated with ________________.

  1. Resistance to insect pests

  2. Resistance to viruses

  3. Resistance to fungi

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

Hairy leaves (trichomes) act as a physical barrier that prevents insects from landing, feeding, or laying eggs, thus providing resistance to pests.

Multiple choice botany plant breeding plant breeding for disease resistance and insect resistance method of plant breeding for crop improvement plant breeding for food production

Pullorum disease of chickens is caused by 

  1. Aspergillus fungus

  2. Paramyxo virus

  3. Salmonella bacterium

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

Pullorum disease is caused by one of the two poultry-adapted strains of Salmonella bacteria. It causes mortality in birds up to 3 weeks of age. Occasionally, it can cause loss in adult birds but also infects parrots, sparrows and peafowl

Multiple choice biology sustainable agriculture patterns of cropping rotation of crops cropping patterns common irrigation systems

Which of the following disease in paddy crop is prevented by cultivating black gram or groundnut after paddy? 

  1. Tungrovirus disease

  2. Spotted bole worm and dried disease

  3. Mosaic disease

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

A.Tungro virus disease is transmitted by leafhoppers, wherein the most efficient vector is the green leafhopper,

B. Spotted bole worm and dried disease - This causes drying and shedding of terminal shoots before flowering. ... Damage is caused by the larvae of the spotted bollworm, Earias vittella, a common pest.

C.Mosaic viruses are plant viruses that cause the leaves to have a speckled appearance

So, the correct option is 'Tungro virus disease'.
Multiple choice botany modes of reproduction alternation of generation in angiosperms alternation of generation angiosperms

Which one of the following has haplontic life cycle ?

  1. Wheat

  2. Funaria

  3. Polytrichum

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

Ustilago is a genus of around 200 smut fungi parasitic on the grasses. In the haplontic life cycle, the haploid stage is multicellular whereas the diploid stage is a single cellular. The zygote undergoes meiosis to form the haploid spores. Each spore germinates are being divided to form gametophyte. The other three are not having this life cycle.

So, the correct answer is option D.

Multiple choice biology living world and classification of microbes pathogen and their mode of transmission economic importance of bacteria and fungi diseases and immunity five kingdoms of living organisms

Asd are formed in _____________.

  1. Ascobolus

  2. Saccharomyces

  3. Penicillium

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

The term 'Asd' is likely a typo for 'Asci' or 'Ascocarps'. Asci are the sexual spore-bearing cells found in Ascomycota fungi, which include Ascobolus, Saccharomyces, and Penicillium.