Importance of Microbes MCQ Quiz in मल्याळम - Objective Question with Answer for Importance of Microbes - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

Concept:

• Microbes and their products have long been used in biotechnological industries for human welfare.
• Microbes like bacteria, fungi, viruses, etc., and their products have been used for their beneficial activities to man.
• Medicine, food, health, agriculture, etc. are some of the industries where microbes are used.
• Probiotic foods are one such product containing bacteria that has proven to be beneficial to humans.

Probiotics:

• Probiotics are active bacteria or yeast that help in maintaining the good health of the digestive system.
• Mode of action:
  • Help restore the population of good bacteria in the body that were lost or had become inactive due to the consumption of antibiotics.
  • The active bacteria present in the probiotics form colonies of useful microbes in the alimentary canal and control the population of other microbes.
  • It decreases the population of harmful microbes inside the body such as Clostridium.
  • Similarly, it increases the population of good bacteria thus helping in digestion.
  • Apart from this it also helps improve resistance and lower the ill effects of harmful substances that are produced during metabolic activities.
• Types of bacteria:
  • Lactobacillus - Most common probiotic. Helps with diarrhea and digestion of lactose.
  • Bifidobacterium - Helps ease the symptoms of irritable bowel syndrome (IBS).
  • Saccharomyces boulardii - It is a species of yeast that works as a probiotic. Helps fight diarrhea and aids in digestion.
• Probiotic foods:
  • Yogurt
  • Kefir
  • Sauerkraut
  • Dark chocolate
  • Miso soups

Additional Information

• ​Bacillus coagulans - is a species of bacteria that is a probiotic that aids in stomach-related ailments.
• Bacteria belonging to the genera Staphylococcus are known to be harmful to humans.
  • Staphylococcus aureus causes diseases in humans such as cellulitis, furuncles, etc.
• Bacteria belonging to the genera Salmonella are harmful to humans.
  • Salmonellosis is a bacterial disease that affects the intestinal tract.
• Clostridium is a genus of bacteria that are known to be found in the intestinal tract of animals. 
  • In humans, they cause diseases such as botulism and tetanus.

So the correct answer is option 1 (Lactobacillus and Bifidobacterium). 

Concept:

• Microbes are present everywhere, in air, water, soil, and inside living bodies, and are diverse- protozoa, bacteria, fungi, viruses, and viroids.
• Microbes are both useful as well as harmful to humans.
• They play an important role in the production of industrial as well as household products.
• Microbes are used to prepare fermented beverages, curd, antibiotics, various chemicals, and enzymes, bioactive molecules, etc.

Explanation:

• Cheese is one of the oldest food items in which microbes are used.
• Different varieties of cheese are known for their texture, flavour, taste, and specificity coming from the microbes used.
• In cheese processing industries, several species of Penicillium and Aspergillus give different flavours to the cheese.
• For example, the flavours of Roquefort cheese are imparted by Penicillium roquefortii.
• The large holes in 'Swiss cheese' are due to the production of CO₂ by the bacteria Propionibacterium shermanii.

Hence, the correct option is (1) Cheese.

Concept:

• Nitrogen fixation is the conversion of atmospheric nitrogen to ammonia (NH₃) under biological and chemical activities.
• It is mainly the conversion of atmospheric nitrogen into usable form which can be taken up by the plants.
• It can be classified into two types-

1. Symbiotic nitrogen fixation - 
   • The nitrogen fixing bacteria stays in symbiosis with the plants.
   • The most common example being the Rhizobium bacteria which stays in the root nodules of the leguminous plants.
   • The bacteria in the root nodules help in fixing the atmospheric nitrogen and make it available for the plants.
2. Asymbiotic nitrogen fixation - 
   • Nitrogen fixation is also carried out by the free living bacteria like Azospirillum and Azotobacter.
   • They live freely and fix nitrogen and are not associated with any plant.

Explanation:

Option 1- Anabaena

• Anabaena is a cyanobacteria.
• It occurs in filamentous form and is present in paddy fields.
• It plays a major role in the atmospheric nitrogen fixation.
• Therefore this option is incorrect.

Option 2- Nostoc

• It is also a cyanobacteria and is involved in the nitrogen fixation.
• Therefore this option is incorrect.

Option 3- Azotobacter

• Azotobacter is a free living soil inhabiting bacteria.
• It is also involved in asymibiotic nitrogen fixation.
• Therefore this option is incorrect.

Option 4- Pseudomonas

• Pseudomonas is not a nitrogen fixing bacteria.
• Therefore this option is correct.

Hence, the correct answer is option (4).

Concept:

• Microbes can be used as biocontrol agents.
• Biocontrol agents are the biological agents like viruses, fungi, insects, bacteria etc. that prevent infection of the host plant by pathogens or the establishment of pathogens in the host plant.
• Different biological methods for controlling plant diseases and pests are being used to reduce dependence on toxic chemicals and insecticides.
• Biocontrol agents do not totally eradicate the pests but helps to keep them at manageable levels.
• Different biocontrol agents are being used nowadays like Baculoviruses, ladybird, dragon flies, Trichoderma etc.

Explanation:

Option 1 - killing insects

• Beetles like Ladybird and Dragonflies are used for getting rid of the aphids and mosquitoes.
• Therefore this option is incorrect.

Option 2 - biological control of plant diseases

• The fungus Trichoderma is used used for biological control of plant diseases and acts against various pathogens.
• Trichoderma species are the free living fungi which are commonly found in the root ecosystem.
• Therefore this option is the correct answer.

Option 3 - controlling butterfly caterpillars

• Butterfly caterpillars can be controlled by the bacteria Bacillus Thuringiensis.
• Dried spores of Bacillus Thuringiensis is available in the market which is mixed in water and sprayed on the plants.
• When they are ingested by the caterpillars, the Bt-toxin gets activated in their gut and cause their death.
• Therefore this option is incorrect.

Option 4 - producing antibiotics

• Several microbes present in the rhizosphere region of the plants produce antibiotics.
• These antibiotics help the plants to get protection from the pathogenic microbes.
• Therefore this option is incorrect.

Hence, the correct answer is option (2).

Concept:

• Methanogenic bacteria are those that grow anaerobically on cellulosic material and produce biogas.
• Biogas contains gases like methane (CH₄), carbon dioxide (CO₂) and hydrogen (H₂).
• Biogas can be used as a fuel in the rural areas where cellulosic materials can easily be found.
• Example of methanogenic bacteria include Methanobacterium, that is commonly used in biogas production.

Explanation:

• Option 1: Rumen of cattle
  • These bacteria help in digesting the cellulose in the cattle rumen and give nutrition to the cattle.
  • Hence, this bacteria is found in rumen of cattle.
• Option 2: Gobar gas plant
  • Gobar gas or biogas plants are the industrial setup for the production of biogas or gobar gas.
  • Here, "gobar" refers to "cow dung" that is used for biogas production.
  • This is because the methanogenic bacteria pass into the cow dung from the cattle rumen and help in biogas production.
  • Thus, the bacteria is found in gobar gas plant.
• Option 3: Bottom of water-logged paddy fields
  • Water-logged paddy fields also contain methogens that produce methane gas, which comes up on surface as bubbles.
  • The water-logging prevents oxygen from penetrating the soil, creating an anaerobic atmosphere for methanogens to grow.
  • Thus, these bacteria are found in such fields.
• Option 4: Activated sludge
  • Activated sludge is produced from flocs of aerobic bacteria during sewage treatment.
  • Since, methanogens grow anaerobically, they are NOT found in activated sludge.

Hence, the correct answer is option (4).

Additional Information

• A biogas plant consists of a 10-15ft deep concrete tank.
• Biowastes are collected here and a slurry of dung (which contains the methanogens) is fed into it.
• A floating cover is placed over the slurry and it keeps rising with increasing biogas production.
• This is connected with an outlet that may be connected to pipelines for supply of the biogas.
• The spent slurry is removed through another outlet and can be used as fertilizer.\
• Biogas plants are essentially more convenient in rural areas where it can have easy access to cattle dung.
• This biogas production technique was developed in India by collective efforts of:
  • Indian Agricultural Research Institute (IARI)
  • Khadi & Village Industries Commission (KVIC)

The correct answer is A and C only

Explanation:

• Household products such as bread, curd, alcoholic beverages, and other fermented items are often prepared using specific microbes. These microbes play a vital role in enhancing the quality, flavor, and nutritional value of these products.
• Some microbes are industrially used for other purposes, such as the production of antibiotics or enzymes, but they are not involved in the preparation of common household products.
  • A) Aspergillus niger: This fungus is commonly used for the industrial production of citric acid and enzymes but is not involved in the preparation of household products.
  • B) Lactobacillus: This bacterium is involved in the preparation of household products like curd and yogurt. It helps in the fermentation of milk, converting lactose into lactic acid.
  • C) Trichoderma polysporum: This fungus is used industrially for the production of cyclosporin, an immunosuppressive drug. It is not involved in the preparation of household products.
  • D) Saccharomyces cerevisiae: Commonly known as baker's yeast, this microbe is widely used in the preparation of bread and alcoholic beverages like beer and wine. It plays a crucial role in fermentation, producing carbon dioxide and ethanol.
  • E) Propionibacterium shermanii: The large holes in ‘Swiss cheese’ are due to the production of a large amount of CO₂ by a bacterium named Propionibacterium sharmanii.

The correct answer is Cyanobacteria

Explanation:

Cyanobacteria:

• Cyanobacteria, also known as blue-green algae, are a phylum of bacteria that obtain their energy through photosynthesis.
• They have specialized cells called heterocysts that are capable of fixing atmospheric nitrogen (N₂) into ammonia (NH₃), which can be utilized by plants.
• This nitrogen-fixing capacity is crucial for enriching soil fertility and supporting plant growth in various ecosystems.

Archaebacteria:

• Archaebacteria, or Archaea, are a group of single-celled microorganisms that are similar to bacteria but have distinct genetic and biochemical properties.
• They are known for living in extreme environments like hot springs, salt lakes, and deep-sea hydrothermal vents.
• While some Archaea can fix nitrogen, they do not possess heterocysts and are not classified as cyanobacteria.

Mycoplasma:

• Mycoplasma are a genus of bacteria that lack a cell wall around their cell membrane, making them unique among prokaryotes.
• They are known for causing various diseases in plants and animals, including humans.
• Mycoplasma are not capable of photosynthesis or nitrogen fixation.

The correct answer is fungus

Explanation:

• Cheese, is one of the oldest food items in which microbes were used.
• Different varieties of cheese are known by their characteristic texture, flavour and taste, the specificity coming from the microbes used.
• For example, the large holes in ‘Swiss cheese’ are due to production of a large amount of CO₂ by a bacterium named Propionibacterium sharmanii.
• The ‘Roquefort cheese’ are ripened by growing a specific fungi on them, which gives them a particular flavour.
• Roquefort cheese is a semisoft cheese. In this cheese, spores of fungus Penicillium roqueforti are added to the curd before final stages of cheese production.

The correct answer is Earthworms.

Explanation-

Earthworms, particularly species like the red wiggler (Eisenia fetida), play a crucial role in vermicomposting due to their eating habits, physiology, and the benefits they provide to the soil. Here's a detailed explanation of why earthworms are used for vermicomposting:

1. Accelerated Breakdown of Organic Material: Worms consume organic waste and decompose it much more quickly than bacteria and fungi alone, turning it into nutrient-rich compost. They're able to speed up the decomposition process due to their eating habits and digestive systems.

2. Enhancement of Nutrient Availability: When organic waste passes through the digestive system of an earthworm, it gets enriched with nutrients that are more easily absorbed by plants. The worm's gut hosts beneficial microbes that help convert the nutrients in the feed into forms that are readily usable by plants.

3. Improvement of Soil Structure: Worms continually tunnel through compost, creating a network of burrows. This process aerates the compost, increasing the oxygen levels which is beneficial for the aerobic bacteria that facilitate the composting process.

4. Production of Beneficial Microorganisms: The digestive process of earthworms encourages the growth of beneficial microorganisms. These beneficial microbes continue to help break down organic matter and make nutrients available to plants even after the compost has been added to the soil.

5. Eco-friendly Waste Management: Vermicomposting is a cost-effective, natural, and eco-friendly method of managing organic waste. It can reduce the amount of waste going to landfill and provides a sustainable solution for recycling kitchen and garden waste into a valuable resource.

6. Worm Castings: The vermicast produced by earthworms contains water-soluble nutrients, which make an excellent, nutrient-rich organic fertilizer and soil conditioner. The castings improve the soil's physical, chemical, and biological properties, therefore enhancing plant productivity.

Conclusion- Earthworms are used in vermicompositing.

Concept:

• Microbes can be used as biocontrol agents.
• Biocontrol agents are the biological agents like viruses, fungi, insects, bacteria etc. that prevent infection of the host plant by pathogens or the establishment of pathogens in the host plant.
• Different biological methods for controlling plant diseases and pests are being used to reduce dependence on toxic chemicals and insecticides.
• Biocontrol agents do not totally eradicate the pests but helps to keep them at manageable levels.
• Different biocontrol agents are being used nowadays like Baculoviruses, ladybird, dragon flies, Trichoderma etc.

Explanation:

Option 1 - killing insects

• Beetles like Ladybird and Dragonflies are used for getting rid of the aphids and mosquitoes.
• Therefore this option is incorrect.

Option 2 - biological control of plant diseases

• The fungus Trichoderma is used used for biological control of plant diseases and acts against various pathogens.
• Trichoderma species are the free living fungi which are commonly found in the root ecosystem.
• Therefore this option is the correct answer.

Option 3 - controlling butterfly caterpillars

• Butterfly caterpillars can be controlled by the bacteria Bacillus Thuringiensis.
• Dried spores of Bacillus Thuringiensis is available in the market which is mixed in water and sprayed on the plants.
• When they are ingested by the caterpillars, the Bt-toxin gets activated in their gut and cause their death.
• Therefore this option is incorrect.

Option 4 - producing antibiotics

• Several microbes present in the rhizosphere region of the plants produce antibiotics.
• These antibiotics help the plants to get protection from the pathogenic microbes.
• Therefore this option is incorrect.

Hence, the correct answer is option (2).