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Identify the fungus with medicinal importance.
  • a)
    Agaricus
  • b)
    Cercospora
  • c)
    Saccharomyces
  • d)
    Penicillium
Correct answer is option 'D'. Can you explain this answer?

Payal Sharma answered
The answer Is D
because it is source of penicillin. a widely used antibiotic(B lactam antibiotic).
penicillin is anti bacterial drug

Heterocysts that take part in nitrogen fixation occur in
  • a)
    Nostoc
  • b)
    Polysiphonia
  • c)
    Ulothrix
  • d)
    Fucus
Correct answer is option 'A'. Can you explain this answer?

Mubeena Akhter answered
Heterocysts contain nitrogenase enzyme which helps to carry out nitrogen fixation.Nostoc show symbiotic association with corralloid roots of cycas and carries out nitrogen fixation.

Methanogens growing anaerobically on cellulosic material produce
  • a)
    Methane and hydrogen
  • b)
    Methane and carbon dioxide
  • c)
    Methane, carbon dioxide and hydrogen.
  • d)
    Methane
Correct answer is option 'C'. Can you explain this answer?

Methanogens are bacteria which grow on cellulosic material and produce a large amount of methane along with CO2 and H2.For example: Methanobacterium
Methanogens are the bacteria found in cattle dung (gobar) and in anaerobic sludge during sewage treatment. They grow anaerobically on cellulosic material and produce a large amount of methane (the main constituent of biogas) along with COand H2. These methanogens are grown on slurry which comprises of cattle dung where they act upon the dung and lead to its breakdown and release of gases like methane and carbon-dioxide. Thus, methanogens are used in biogas production.

Rennin used in the cheese industry is
  • a)
    Alkaloid
  • b)
    Enzyme
  • c)
    Antibiotic
  • d)
    Inhibitor
Correct answer is option 'B'. Can you explain this answer?

Poornima Poori answered
Reninn also called as chymosin protein digesting enzymes that curdles milk by transforming caseinigen into indulge casein it is found only in the fourth stomach of cud chewing animals such as cows its action extend the period in which milk is retained in the stomach of the young animal in animal that reninn milk is coagulated by the action of person as the case in humans A commercial form of reninn and rennet is used in manufacturing cheese and preparing junket also .

Which one of the following microbes is used in the commercial production of ethanol?
  • a)
    Streptococcus spp.
  • b)
    Clostridium butyricum
  • c)
    Trichoderma polysporum
  • d)
    Saccharomyces cerevisiae
Correct answer is option 'D'. Can you explain this answer?

Ishita Joshi answered
Microbe Used in Commercial Production of Ethanol

The microbe used in the commercial production of ethanol is Saccharomyces cerevisiae.

Explanation

Saccharomyces cerevisiae is a yeast that is commonly used in the fermentation process to produce ethanol. It is a single-celled organism that feeds on sugar and converts it into alcohol and carbon dioxide. In the production of ethanol, Saccharomyces cerevisiae is added to a mixture of sugar and water, which is then left to ferment for a period of time. During this process, the yeast consumes the sugar and produces ethanol as a by-product.

Advantages of Using Saccharomyces cerevisiae

There are several advantages to using Saccharomyces cerevisiae in the production of ethanol:

1. High Yield: Saccharomyces cerevisiae is known for its high ethanol yield, which makes it a popular choice for commercial producers.

2. Fast Fermentation: Saccharomyces cerevisiae is a fast-fermenting yeast, which means that it can produce ethanol quickly.

3. Easy to Handle: Saccharomyces cerevisiae is easy to handle and can be stored for long periods of time.

4. Cost-effective: Saccharomyces cerevisiae is a cost-effective option for ethanol production.

Conclusion

In conclusion, Saccharomyces cerevisiae is the microbe used in the commercial production of ethanol. It is a fast-fermenting yeast that is known for its high ethanol yield and is cost-effective to use.

The term antibiotic was first used by
  • a)
    Pasteur
  • b)
    Lister
  • c)
    Waksman
  • d)
    Flemming
Correct answer is option 'C'. Can you explain this answer?

Anjana Sharma answered
Selman Waksman, the microbiologist who discovered streptomycin, first used the word "antibiotic" in the medical sense in 1943. Science historian Howard Markel talks about how it was actually a naval officer who first coined "antibiotic" in 1860, to describe an opposition to the belief in life beyond Earth

Probiotics are
  • a)
    Live microbial food supplement
  • b)
    New kind of food allergens
  • c)
    Cancer inducing microbes
  • d)
    Safe antibiotics
Correct answer is option 'A'. Can you explain this answer?

Probiotics are live bacteria and yeasts that are good for you, especially your digestive system. We usually think of these as germs that cause diseases. But your body is full of bacteria, both good and bad. Probiotics are often called "good" or "helpful" bacteria because they help keep your gut healthy. You can find probiotics in supplements and some foods, like yogurt. Doctors often suggest them to help with digestive problems. When you lose "good" bacteria in your body, for example after you take antibiotics, probiotics can help replace them. They can help balance your "good" and "bad" bacteria to keep your body working the way it should.

Lactic acid is formed by the process of
  • a)
    Fermentation
  • b)
    Glycolysis
  • c)
    HMP Pathway
  • d)
    None of these
Correct answer is option 'A'. Can you explain this answer?

Azeem answered
Fermentation is the process of producing ATP in the absence of oxygen, through glycolysis alone. that the glycolysis breaks a glucose molecule into two pyruvate molecules, producing a net gain of two ATP and two NADH molecules.

The residue left after methane production from cattle dung is
  • a)
    Used as manure
  • b)
    Buried in landfills
  • c)
    Used in civil construction
  • d)
    Burnt
Correct answer is option 'A'. Can you explain this answer?

Vijay Bansal answered
The raw material for biogas production is excreta (dung) of cattle. The biogas plant consists of a concrete tank (10-15 feet deep) in which bio-wastes are collected and slurry of dung is fed. A floating cover is placed over the slurry, which keeps on rising as the gas is produced in the tank due to the microbial activity. Methano bacterium in the dung act on the bio-wastes to produce bio-gas. The gas produced is supplied to nearby houses by an outlet. Through another outlet, the spent slurry is removed to be used as manure. 

A common biocontrol agent for the control of plant disease is 
  • a)
    Baculovirus
  • b)
    Bacillus thuringiensis
  • c)
    Glomus
  • d)
    Trichoderma
Correct answer is option 'D'. Can you explain this answer?

Aryan Dasgupta answered
Introduction to Biocontrol Agents
Biocontrol agents are organisms that are used to control pests and diseases in plants. Among various biocontrol agents, Trichoderma is widely recognized for its effectiveness in managing plant diseases.
What is Trichoderma?
- Trichoderma is a genus of fungi that are commonly found in soil and decaying plant material.
- These fungi are known for their ability to promote plant growth and suppress diseases.
Mechanisms of Action
- Antagonism: Trichoderma species can outcompete pathogenic fungi for resources and space, effectively reducing their populations.
- Mycoparasitism: Certain Trichoderma species directly invade and degrade the cells of pathogenic fungi, leading to their demise.
- Induced Resistance: Trichoderma can stimulate the plant's immune system, enhancing its resistance to diseases.
Advantages of Using Trichoderma
- Non-toxic: Unlike chemical fungicides, Trichoderma is environmentally friendly and safe for non-target organisms, including humans and beneficial insects.
- Soil Health: Trichoderma contributes to soil health by enhancing nutrient availability and promoting microbial diversity.
- Cost-effective: Utilizing Trichoderma can reduce the reliance on chemical inputs, leading to cost savings for farmers.
Conclusion
In summary, Trichoderma stands out as a potent biocontrol agent for managing plant diseases due to its multifaceted mechanisms of action and numerous benefits. Its use not only helps in controlling pathogens but also supports sustainable agricultural practices, making it an invaluable tool in modern agriculture.

Select the correct group of biocontrol agents:
  • a)
    Nostoc, Azospirillum, Nucleopolyhedrovirus
  • b)
    Bacillus thuringiensis, Tobacco mosaic virus, Aphids
  • c)
    Trichoderma, Baculovirus, Bacillus thuringiensis
  • d)
    Oscillatoria, Rhizobium, Trichoderma
Correct answer is option 'C'. Can you explain this answer?

Lead Academy answered
Biocontrol agents are organisms used to control pests or pathogens biologically.
Trichoderma is a fungus used against plant pathogens.
Baculovirus (like Nucleopolyhedrovirus) is used to target insect pests.
Bacillus thuringiensis is a bacterium producing toxins effective against insects.
Hence, Option C correctly lists known biocontrol agents.

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