Tag: useful and harmful fungi

Questions Related to useful and harmful fungi

Which of the following produces citric acid through fermentation process?

  1. Aspergillus

  2. Streptococcus

  3. Acetobacter

  4. Streptomyces


Correct Option: A
Explanation:
  • Aspergillus produces citric acid through fermentation process.
  • Streptococcus  produces lactic acid through fermentation.
  • Acetobacter produces acetic acid through fermentation.
  • Streptomyces produces antibiotics.
  • So, the correct answer is 'Aspergillus'.

Lipid dissolving enzymes are obtained from

  1. Trichoderma

  2. Streptococcus

  3. Candida

  4. Mucor


Correct Option: C
Explanation:
  • Candida is the fungus that causes infection on the skin or the mucous membrane.
  • The cells of the fungus in order to infect the host cell needs to break the cell membrane and enter the cell. For this purpose the fungi secrets phospholipase and lipase to dissolve the cell membrane which is made us of the lipid bilayer with units of phospholipid present in it.
  • After entering the cell the fungi starts growing on the cell in a parasitic way. The secretions which are released by the fungus cause itching and rashes on the area of infection.
  • Whereas Trichoderma is not an infectious agent but it lives in a symbiotic relationship with many plants. Some species of Trichoderma maybe pathogenic but only to plants.
  • Streptococcus is a disease-causing organism but it causing the disease using the process of hemolytic where it mainly attacks the blood cells and causing their lysis.
  • Mucor is fungus whose growth is seen on the stale bread. It is black colour mold growing on the bread.
  • Therefore the answer Option C is correct as Candida is the only one among the options that secrets lipid dissolving enzymes.

Which of the following is an application of fermentation

  1. Tanning of leather

  2. Curing of tea

  3. Production of wine

  4. All of the above


Correct Option: D
Explanation:
  • Fermentation in the process of tanning leather is used to soften the skin after removing the hair. This done using various bacteria.
  • fermention in curing of tea takes place after the process of disruption. Here the chlorophyll in the ;eves is enzymatically broken and its tannins are released.
  • In production of wine the organism used for fermentation to convert carbohydrate in alcohol.

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


Correct Option: C
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'.

The importance of fungi in food web lies in the fact that

  1. They are photoautotrophs.

  2. They have prokaryotic cell structure.

  3. They serve as key decomposers of dead organic matter.

  4. They generate antibiotics that kill competing plants and animals.


Correct Option: C
Explanation:
  • Fungus are an important part of the saprophytic food chain.
  • They decompose the organic waste left by other animals and convert it into inorganic components that can be again absorbed by the plants ie the organisms of the first trophic level of the food chain and enter the food chain again.
  • So, the correct answer is 'They serve as key decomposers of dead organic matter'.

Calcium gluconate is widely used as a source of calcium for infants. It is prepared from

  1. Rhizopus

  2. Aspergillus

  3. Mucor

  4. None of the above


Correct Option: B
Explanation:

Aspergillus niger is filamentous fungi that cause disease on vegetables and fruits called black mould. These organisms are used in fermentation processes to obtain citric acid and gluconic acid that are of commercial importance. It is also used in the manufacture of calcium gluconate. This compound is given to infants from hypocalcemia. Thus, the correct answer is option B.