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Chapter 8 · Microbes in Human Welfare

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#1 SUB 🖼 1

Question

How LABs are useful to us? Explain.
OR
Give a brief account on importance of Lactobacillus bacteria in household products.

Answer

LAB is lactic acid bacteria.
They grow in milk and convert it to curd.
During growth, the LAB produces acids that coagulate and partially digest the milk proteins.
A small amount of a curd added to the fresh milk as inoculum or starter contain millions of LAB, which at suitable temperature multiply, thus converting milk to curd.
LAB improves milk quality by increasing vitamin B12.
In our stomach too, the LAB play very beneficial role in checking disease causing microbes.
#2 SUB 2M

Question

Explain in short : Microbes are omnipresent.

Answer

Protozoa, Bacteria, Fungi, Microscopic plant virus, Viroids, and prions etc. are microorganisms.
Microorganisms are found in soil, water, inside our body and that of other animals and plants.
They are present even at sites where no other life-form could possibly exist.
Microbes are found at deep inside the geysers thermal vents where temperature may be as high as 100°C.
Microbes are also found deep in the soil, under the layers of snow several metres thick, and in highly acidic environments.
#3 SUB 4M

Question

Microbes are useful in household products. Explain this with suitable examples.
OR
What are the uses of bacteria and fungi in our daily life?
OR
Write uses of miceo-Orgunisms in house-hold pruducts. (JUNE 2025)
OR
Microbes produce gases during metabolism. Explain with suitable examples.

Answer

We useful microbes for various purposes. Some products are derived from them everyday. Such as -
#4 SUB 2M

Question

Explain the role of different micro organisms in the production of cheese.

Answer

Cheese is an edible substance. Microbes are used at different stages of cheese making.
Different varieties of cheese are known by their characteristic texture, flavour and taste which is given by specific microbes used in the cheese production.
The large holes in “Swiss cheese” are due to production of a large amount of carbon dioxide by a bacterium named Propionibacterium sharmanii.
The “Roquefort cheese” are ripened by growing a specific fungi (Penicillium Roquefortii) on them, which gives them a particular flavour.
#5 SUB 2M

Question

Why Saccharomyces cerevisiae is known as baker's and brewer's yeast? Explain.

Answer

Saccharomyces cerevisiae is a fungi (yeast).
The dough, which is used for making bread, is fermented using Saccharomyces cerevisiae, called baker’s yeast.
This yeast is also, used for production of ethanol from the fermentation of cereals and fruit juices, so it is called brewer’s yeast.
#6 SUB 🖼 1

Question

Give the name of some traditional Indian recipes which are made from wheat, rice and chickpeas and the name of microbes used in.

Answer

Recipe :
(1) Wheat: bread, cake etc
(2) Rice: Dosa, Idli etc.
(3) Chickpeas: dhokla, khandavi, gatta etc.
Microbes:

(1) Bacteria: Lactobacillus

(2) Yeast-fungi: Saccharomyces cerevisiae

#7 SUB 2M

Question

What are fermentors? Describe alcoholic beverages.

Answer

Many useful products for mankind are produced or synthesized by using microbes at industrial level
Beverages and antibiotics are examples of this.
For industrial production, useful microbes are grown into a big vessel which is called fermentors.
Microbes have been used from time immemorial for the production of beverages like wine, beer, whiskey brandy, rum.
Saccharomyces cerevisiae (brewer’s) yeast is used to produce ethanol from cereals and fruit juices.
Yeast produces ethanol by an anaerobic respiration pathway.
Depending on the type of the raw material used for fermentation and the type of processing (with or without distillation) different types of alcoholic drinks are obtained.
Wine and beer are produced without distillation.
Whisky, brandy and rum are produced by distillation.
#8 SUB

Question

Write about the microbes which play significant role in controlling of pathogenic bacteria?

Answer

Some microbes are used to prepare drugs.
Antibiotics which is produced by the use of microbes, inhibits the growth of pathogens or kill them.
These drugs commonly derived from fungi and bacteria. e.g.
(1) Penicillium notatum (fungus) secrete penicillin antibiotic which inhibits or slow down the growth of Staphylococci bacterium.
Antibiotics weaken the cell wall of bacteria. Such weak bacteria are destroyed by immune cells WBC.
(2) Streptomysin, tetracyclin, penicillin etc. are common antibiotics.
#9 SUB 3M 🖼 1

Question

Microbes are used for industrial production of certrain useful products / substances on a large scale. Explain with examples.

Answer

Many products which are useful for mankind are produced by microbes on industrial level. For example: vinegar, beverages, antibiotics, chemicals, enzymes and other biochemical molecules.
Saccharomyces cerevisiae– Yeast is used to prepare vinegar, wine, beer, whiskey, brandy or rum like beverages and also, used for bread making.
Saccharomyces cerevisiae (brewer’s) yeast is used to produce ethanol from cereals and fruit juices.
Antibiotics are chemical substances which are produced by microbes. They kill pathogenic microbes or slow down their growth. For example: Penicillin
We cannot imagine a world without antibiotics.
Microbes are also used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes.
Examples :

Microbes

Product

1.

Aspergillus niger

Citric acid

2.

Acetobacter aceti

Acetic acid

3.

Clostridium butyricum

Butyric acid
Q.10.Describe the role of microbes in the production of bioactive molecules.
OR
State the sources and uses of statins and cyclosporin A.
OR
Find out the name of the microbes from which cyclosporin A (an immunosuppressive drug) and statins (Blood cholesterol lowering agents) are obtained.
Ans. (1) Cyclosporin A :
It is derived from Trichoderma polysporum fungi.
This bioactive molecule is used as immunosuppressive drug in organ transplant patients.
(2) Statins :
It is derived from Monascus purpureus, a yeast.
This drug is used as blood cholesterol lowering agent.
#10 SUB 2M

Question

What are antibiotics? Antibiotic production is the most significant discoveries of the 20th century. Explain with examples.
OR
How was first antibiotic discovered? Explain.
OR
Explain Antibiotics.
Or
Discovery of antibiotics is a chance discovery.
– Explain.

Answer

Antibiotics are chemical substances which are produced by microbes. It kills pathogenic microbes or slow down their growth.
These chemicals are called antibiotics.

(anti = opposite, bio = life)

e.g. Penicillin is the first discovered antibiotic.

Discovery :

  • Alexander Fleming while working on Staphylococci bacteria , once observed a mould growing in one of his unwashed culture plates around which Staphylococci could not grow.
  • He found that it was due to a chemical produced by the mould and he named it penicillin after the mould Penicillium notatum.
  • However, its full potential as an effective antibiotic was established much later by Ernest Chain and Howard Florey.
  • This antibiotic was extensively used to treat American soldiers wounded in world war II
  • Fleming, Ernest Chain and Howard Florey were awarded the Nobel prize in 1945, for this discovery.
#11 SUB 3M

Question

Explain the role of microbes in the production of chemicals, enzymes and other bioactive molecules.

Answer

Microbes are also used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes.
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#1 SUB

Question

Three water samples namely river water, untreated sewage water and secondary effluent discharged from sewage treatment plant were subjected to BOD test. The samples were labelled in A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20 mg/L, 8mg/L and 400mg/L, respectively. Which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean?

Answer

BOD refers to the amount of the oxygen that would be consumed if all the organic matter in one liter of water were oxidised by bacteria.
The greater the BOD of waste water, more is its polluting potential
Water having least BOD is less polluted or river water.
Sample A (20 mg/L) is effluent which is obtained from after the secondary sewage treatment.
Sample B (8mg/L) is a river water.
Sample C (400mg / L) is not treated in sewage treatment plant.
Reason :
Sample C is the highly polluted water as the BOD is high.
Conclusion :
BOD of a river water is least among three very high. So, we can say that river water is clean as compared to other two samples.
#2 SUB 2M

Question

Describe primary treatment of sewage treatment plant. OR
Explain Primary Treatment of sewage.(JULY 2022, MAY 2021)

Answer

Primary treatment steps basically involve physical removal of particles large and small from the sewage through filtration and sedimentation. These are removed in stages; initially, floating debris is removed by sequential filtration.
Then the grit soil and small pebbles are removed by sedimentation.
All solids that settle from the primary sludge and the supernatant from the effluent. The effluent from the primary settling tank is taken for secondary treatment.
#3 SUB 2M

Question

Mention the importance of methanogens bacteria.

Answer

Certain bacteria which grow anaerobically on cellulosic material produce large amount of Methane along with CO2 and H2. These bacteria are collectively called methanogens, and one such common bacterium is Methanobacterium.
These bacteria are commonly found in the anaerobic sludge during sewage treatment.
These bacteria are also present in the rumen, (a part of stomach) of cattle. A lot of cellulosic material present in the food of cattle is also present in the rumen.
In rumen, these bacteria help in the breakdown of cellulose and play an important role in the nutrition of cattle.
The excreta (dung) of a cattle, commonly called gobar, is rich in these bacteria.
Dung can be used for generation of biogas, commonly called gobar gas.
#4 SUB 2M

Question

Certain bacteria are useful to mankind in many ways. Give examples.

Answer

The given microbes give useful products to us.

Bacteria

Use / Product

1.

Lactobacillus

Curd

2.

Saccharomyces cerevisiae

To prepare bread and alcoholic beverages.

3.

Propionibacterium sharmanii

Swiss cheese

4.

Penicillium roquefortii

Roquefort cheese

5.

Aspergillus niger fungi

Citric acid

6.

Acetobacter aceti

Acetic acid

7.

Clostridium butyricum

Butyric acid

8.

Penicillium notatum

Penicillin

9.

Streptococcus

Streptokinase enzyme which is used as a clot buster
#5 SUB 🖼 1

Question

What is sewage? How sewage is harmful for us?

Answer

Large quantities of waste water is generated everyday in cities and towns. A major component of this waste water is human excreta. This municipal waste water is also called sewage.
It contains large amounts of organic matter and microbes, many of which are pathogenic.
This cannot be discharged into natural water bodies like rivers and streams directly.
Before disposal, hence, sewage is treated in Sewage Treatment Plant (STPs) to make it less polluting.
Sewage / untreated water harmful to us because the pollutants and pathogens in sewage cause water-borne animal disease like typhoid, cholera etc.
Sewage cannot be discharged into natural water bodies like rivers and streams directly.
Before disposal, hence, sewage is treated in sewage treatment plants (STPs) to make it less polluting.
#6 SUB 4M

Question

What is sewage? Describe secondary treatment (biological treatment) in sewage treatment plant.
OR
Explain biological treatment in sewage treatment. (diagram is not required)
OR
Explain biological treatment of sewage treatment plant.

Answer

Large quantities of waste water are generated everyday in cities and towns. A major component of this waste water is human excreta. This municipal waste water is also called sewage.
It contains large amounts of organic matter and microbes, many of which are pathogenic.
This cannot be discharged into natural water bodies like rivers and streams directly.
Before disposal, hence, sewage is treated in Sewage Treatment Plant (STPs) to make it less polluting.
Treatment of waste water is done by heterotrophic microbes naturally present in the sewage.
There are two stages of the process:

(1) Primary treatment

(2) Secondary treatment (biological treatment)

The following sequential treatment is done in secondary treatment.

(1) The primary effluent is passed into large aeration tanks, where it is constantly agitated mechanically and air is pumped into it.

This allows vigorous growth of useful aerobic microbes form flocs (masses of bacterial associated with fungal filaments to form mesh like structures).
While growing, these microbes consume the major part of the organic matter in the effluent.
This results in significant reduction of the BOD (Biochemical Oxygen Demand) of the effluent.
The greater the BOD of waste water, the more is its polluting potential.
Once the BOD of sewage or waste water is reduced significantly, the effluent is then passed into a settling tank.
Where bacterial ‘flocs’ are allowed to sediment. This sediment is called activated sludge.

(2) A small part of the activated sludge is pumped back into the aeration tank to serve as the inoculum.

(3) The remaining major part of the sludge is pumped into large tanks called anaerobic sludge digesters.

Here, other kinds of bacteria, which grow anaerobically, digest the bacteria and the fungi in the sludge.
During this digestion, bacteria produce a mixture of gases from the biogas such as carbon dioxide, methane and hydrogen. (CO2, CH4 and H2) These gases from biogas and can be used as source of energy as it is inflammable.
#7 SUB 🖼 1

Question

What is the key difference between primary and secondary treatment?

Answer

Sewage treatment plant contains mainly two steps :

Primary treatment

Secondary treatment (biological treatment)

1.

Primary treatment steps basically involve physical process during which removal of particles- large and small is done from the sewage.

1.

This is a biological process in which organic matter is decomposed by microbes.

2.

This process, filtration and sedimentation are done repeatedly.

2.

Here, by using aerobic and anaerobic microbes, organic matter is decomposed.

3.

This treatment is less expensive and comparatively simple process.

3.

This process is complex and expensive.
#8 SUB 4M 🖼 1

Question

Explain the structure and working of biogas plant with diagram.
OR
Draw a typical biogas plant and explain in detail.

Answer

10-15 feet deep concrete tank is prepared for biogas plant.
This tank is fed by collected bio-waste and a slurry.
A floating cover is placed over the slurry.
Due to microbial activity (Methanogens) this slurry keeps rising as the gas is produced.
The biogas plant has an outlet.
This is connected to a pipe to supply biogas to nearby houses.

The spent slurry is removed through another outlet and may be used as a fertiliser.
The biogas plants are more often built in rural areas.
The biogas thus produced is used for cooking and lighting.
In biogas plant, bacteria produce a mixture of gases from biogas such as carbon dioxide, methane and hydrogen. (CO2, CH4 and H2)
These bacteria are collectively called as Methanobacterium.
#9 SUB 2M 🖼 1

Question

Do you think microbes can also be used as source of energy? If yes, how?
OR
Role of microbes in production of biogas.

Answer

Yes, microbes are used as a source of energy.
For example microbes are used to produce biogas or gobar gas from dung and bio waste.
Biogas (gobar gas) is a product of anaerobic respiration of which main component is methane gas.
The spent slurry from the biogas plant is used as fertiliser.
#10 SUB

Question

The use of biocontrol measures will greatly reduce our dependence on toxic chemicals and pesticides.
OR
Give an importance of virus included in genus Nucleopolyhedrovirus. (March 2023)
OR
How microbes are useful as Biocontrol agents? Explain.
OR
Explain biocontrol agent which are pathogens that attack insects and other arthropods.

Answer

In agriculture, there is a method of controlling pests that relies on natural predation rather than introduced chemicals.
A key belief of the organic farmers is that biodiversity promotes health.
The use of biocontrol measures will greatly reduce our dependence on toxic chemicals and pesticides.
An important part of the biological farming approach is to become familiar with the various life forms that inhabit the field, predators as well as pests, and also their life cycles, patterns of feeding and the habitats that they prefer. This will help develop appropriate means of biocontrol.
Different biocontrol agents are as follows:

(1) Ladybird and Dragonflies :

  • These beetles are useful to get rid of aphids and mosquitoes.

(2) Bacillus thuringiensis:

  • An example of microbial biocontrol agents that can be introduced in order to control butterfly caterpillars is the bacteria Bacillus thuringiensis (often written as Bt).
  • These are available in sachets as dried spores which are mixed with water and sprayed onto vulnerable plants such as brassicas and fruit trees, that are where eaten by the insect larvae.
  • In the gut of the larvae, the toxin is released and the larvae get killed.
  • The bacteria will kill the caterpillars, but leave other insects unharmed.
  • The scientists have introduced Bt toxin genes into plants. Such plants are resistant to attack by insect pests.

(3) Trichoderma :

  • Trichoderma species are free living fungi that are very common in root ecosystems.
  • These fungi are used as biocontrol agent for the treatment of plant disease.
  • They are effective biocontrol agents of several plant pathogens.

(4) Baculoviruses :

  • The majority of baculoviruses used as biocontrol agents are of genus Nucleopolyhedrovirus.
  • Baculoviruses are pathogens that attack insects and other arthropods.
Various biocontrol agents have shown no negative impacts on plants, mammals, birds, fish or even on non target insects.
Inspite of this, they are desirable when beneficial insects are being conserved to aid in an overall Integrated Pest Management (IPM) programme, or when an ecologically sensitive area is being treated.

#11 SUB 🖼 2

Question

Microbes can be used to decrease the use of chemical fertilisers and pesticides. Explain how this can be accomplished.
OR
How do biofertilisers increase the fertility of soil?
OR
Describe the importance of microbes as
bio-fertilisers.

Answer

Due to our present day life styles, environmental pollution is a major cause of concern.
The use of chemical fertilisers to meet the ever-increasing demand of agricultural produce has contributed significantly to this pollution.
There are problems associated with the overuse of chemical fertilisers and there is a large pressure to switch to organic farming – the use of biofertilisers.
Biofertilisers are organisms that enrich the nutrient quality of the soil.
The main sources of biofertilisers are bacteria, fungi and cyanobacteria.
The nodules on the roots of leguminous plants are formed by the symbiotic association of Rhizobium.
These bacteria fix atmospheric nitrogen into organic forms, which is used by the plant as nutrient.
Other bacteria can fix atmospheric nitrogen while free-living in the soil Azospirillum and Azotobacter, enriching the nitrogen content of the soil.
Fungi are also known to form symbiotic associations with plants (mycorrhiza).
Many members of the genus Glomus form mycorrhiza.
The fungal symbiont in these associations absorbs phosphorus from soil and passes it to the plant.
In paddy fields, Cyanobacteria serve as an important biofertiliser.
Currently, in our country, a number of biofertilisers are available commercially in the market and farmers use these regularly in their fields to replenish soil nutrients and to reduce dependence on chemical fertilisers.
In agriculture, there is a method of controlling pests that relies on natural predation rather than introduced chemicals.
#12 SUB 🖼 1

Question

Find out the role of microbes in the following and discuss it with your teacher.
(a) single cell protein (SCP)
(b) soil

Answer

(a) Single cell protein (SCP)
The source of single cell protein is a non harmful bacteria which is an alternative source of good protein.
For example; edible mushrooms (fungi) which is used by human is a source of protein.
Microbes can be cultured on industrial waste to produce protein.
Microbes like Spirulina and Methylophilus methylotropus can easily grow on materials like waste water from potato processing plants, straw, molasses, animal manure and waste water sewage to produce large quantities and can serve as food rich in protein, minerals, fats, carbohydrates and vitamins.
(b) Soil
For the fertility of soil, microbes play an important role.
By decomposition of organic matter, microbes enrich the soil with nutrients.
Many species of bacteria and cyanobacteria can fix atmospheric nitrogen into the soil.
Example : Symbiotic bacterium : Rhizobium
Free living bacterium : Azospirillum and Azotobacter
Cyanobacteria : Anabena, Nostoc and Oscillatoria
#13 SUB 🖼 1

Question

Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes with the help of a microscope, which sample would you carry and why?

Answer

Curd can be used as a sample for the study of microbes. Curd contains numerous lactic acid bacteria (LAB) or Lactobacillus.
These bacteria produce acids that coagulate and digest milk proteins.
A small drop of curd can be carried to the biology laboratory because it contains multitude of bacteria, which can be easily observed under a microscope which are of various shapes and sizes.
#14 SUB 🖼 1

Question

Give any two names of fungi used for antibiotic synthesis.

Answer

(i) Penicillium notatum (ii) Streptomyces
#15 SUB 🖼 1

Question

Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. (Biogas, Citric acid, Penicillin and Curd)

Answer

Penicillin > Biogas > Curd > Citric acid.
S src: Multiple Choice Questions (MCQs) match 85% type: 138 Q ⤓ Export ZIP
#1 MCQ 1M

Question

The technology of biogas production from cow dung was developed in India largely due to the efforts of:

Options

  1. (A) Gas Authority of India
  2. (B) Oil and Natural Gas Commission
  3. (C) Indian Agricultural Research Institute and Khadi and Village Industries Commission
  4. (D) Indian Oil Corporation.

Answer

(C) Indian Agricultural Research Institute and Khadi and Village Industries Commission

#2 MCQ 1M

Question

Big holes in Swiss cheese are made by a:

Options

  1. (A) a machine
  2. (B) a bacterium that produces methane gas
  3. (C) a bacterium producing a large amount of carbon dioxide
  4. (D) a fungus that releases a lot of gases during its metabolic activities.

Answer

(D) a fungus that releases a lot of gases during its metabolic activities.

#3 MCQ 1M

Question

The vitamin whose content increases following the conversion of milk into curd by lactic acid bacteria is:

Options

  1. (A) vitamin C
  2. (B) vitamin D
  3. (C) vitamin B12
  4. (D) vitamin E.

Answer

(C) vitamin B12

#4 MCQ 1M

Question

Methanogens do not produce:

Options

  1. (A) Oxygen
  2. (B) Methane
  3. (C) Hydrogen sulphide
  4. (D) Carbon dioxide.

Answer

(A) Oxygen

#5 MCQ 1M

Question

Waste water treatment generates a large quantity of sludge, which can be treated by:

Options

  1. (A) anaerobic digesters
  2. (B) flocs
  3. (C) chemicals
  4. (D) oxidation pond.

Answer

(A) anaerobic digesters

#6 MCQ 1M

Question

Methanogenic bacteria are not found in:

Options

  1. (A) rumen of cattle
  2. (B) gobar gas plant
  3. (C) bottom of water-logged paddy fields
  4. (D) activated sludge.

Answer

(D) activated sludge.

#7 MCQ 1M ▦ 1

Question

Match the following list of bacteria and their commercially important products:
Choose the correct match:

Bacterium

Product

A

Aspergillus niger

i

Lactic acid

B

Acetobacter aceti

ii

Butyric acid

C

Clostridium butyricum

iii

Acetic acid

D

Lactobacillus

iv

Citric acid

Options

  1. (A) A – ii, B – iii, C – iv, D – i
  2. (B) A – ii, B – iv, C – iii, D – i
  3. (C) A – iv, B – iii, C – ii, D – i
  4. (D) A – iv, B – i, C – iii, D – ii

Answer

(C) A – iv, B – iii, C – ii, D – i

#8 MCQ 1M ▦ 1

Question

Match the items in Column ‘I’ and Column ‘II’ and choose correct answer.
The correct answer is:

Column I

Column II

A

Lady bird

i

Methanobacterium

B

Mycorrhiza

ii

Trichoderma

C

Biological control

iii

Aphids

D

Biogas

iv

Glomus

Options

  1. (A) A-ii, B-iv, C-iii, D-i
  2. (B) A-iii, B-iv, C-ii, D-i
  3. (C) A-iv, B-i, C-ii, D-iii
  4. (D) A-iii, B-ii, C-i, D-iv

Answer

(B) A-iii, B-iv, C-ii, D-i

#9 MCQ 1M

Question

Which one of the following alcoholic drinks is produced without distillation?

Options

  1. (A) Wine
  2. (B) Whisky
  3. (C) Rum
  4. (D) Brandy

Answer

(A) Wine

#10 MCQ 1M ▦ 1

Question

Match the following list of bioactive substances and their roles:
Choose the correct match:

Bioactive Substance

Role

A

Statin

i

Removal of oil stains

B

Cyclosporin A

ii

Removal of clots from blood vessels

C

Streptokinase

iii

Lowering of blood cholesterol

D

Lipase

iv

Immuno-suppressive agent

Options

  1. (A) A – ii, B – iii, C – i, D – iv
  2. (B) A – iv, B – ii, C – i, D – iii
  3. (C) A – iv, B – i, C – ii, D – iii
  4. (D) A – iii, B – iv, C – ii, D – i

Answer

(D) A – iii, B – iv, C – ii, D – i

#11 MCQ 1M

Question

The primary treatment of waste water involves the removal of:

Options

  1. (A) dissolved impurities
  2. (B) stable particles
  3. (C) toxic substances
  4. (D) harmful bacteria.

Answer

(B) stable particles

#12 MCQ 1M

Question

BOD of waste water is estimated by measuring the amount of:

Options

  1. (A) total organic matter
  2. (B) biodegradable organic matter
  3. (C) oxygen evolution
  4. (D) oxygen consumption

Answer

(D) oxygen consumption

#13 MCQ 1M

Question

Mycorrhiza does not help the host plant in:

Options

  1. (A) Enhancing its phosphorus uptake capacity
  2. (B) Increasing its tolerance to drought
  3. (C) Enhancing its resistance to root pathogens
  4. (D) Increasing its resistance to insects.

Answer

(D) Increasing its resistance to insects.

#14 MCQ 1M

Question

Which one of the following is not a nitrogen-fixing organism?

Options

  1. (A) Anabaena
  2. (B) Nostoc
  3. (C) Azotobacter
  4. (D) Pseudomonas

Answer

(D) Pseudomonas

#15 MCQ 1M

Question

The residue left after methane production from cattle dung is:

Options

  1. (A) burnt
  2. (B) buried in land fills
  3. (C) used as manure
  4. (D) used in civil construction

Answer

(C) used as manure

#16 MCQ 1M

Question

Activated sludge should have the ability to settle quickly so that it can:

Options

  1. (A) be rapidly pumped back from sedimentation tank to aeration tank
  2. (B) absorb pathogenic bacteria present in waste water while sinking to the bottom of the settling tank
  3. (C) be discarded and anaerobically digested
  4. (D) absorb colloidal organic matter.

Answer

(A) be rapidly pumped back from sedimentation tank to aeration tank

#17 MCQ 1M

Question

Micro organisms such as Lactobacillus is commonly called

Options

  1. (A) Citric Acid Bacteria (CAB)
  2. (B) Lactic Acid Bacteria (LAB)
  3. (C) Tartaric Acid Bacteria (TAB)
  4. (D) Formic Acid Bacteria (FAB)

Answer

(B) Lactic Acid Bacteria (LAB)

#18 MCQ 1M

Question

Which bacterium is responsible for large holes in 'Swiss cheese' are due to the production of a large amount of CO2 ?

Options

  1. (A) Propionibacterium
  2. (B) Aspergillus niger
  3. (C) LAB
  4. (D) Saccharomyces cerevisiae

Answer

(A) Propionibacterium

#19 MCQ 1M

Question

Dough kept overnight in warm weather becomes soft and spongy because of

Options

  1. (A) Cohesion
  2. (B) Osmosis
  3. (C) Absorption of carbon dioxide from atmosphere
  4. (D) Fermentation

Answer

(D) Fermentation

#20 MCQ 1M

Question

Which of the following process is performed by yeast cell ?

Options

  1. (A) Transpiration
  2. (B) Pasteurization
  3. (C) Fermentation
  4. (D) Effervescence

Answer

(C) Fermentation

#21 MCQ 1M

Question

The bread is soft and porous when the yeast cells are mixed in the lump of wheat flour because :

Options

  1. (A) Yeast produce benzoic acid
  2. (B) Evolution of CO2 makes the bread spongy
  3. (C) Yeast is soft and flour also becomes soft
  4. (D) Yeast produces acetic acid and alcohol which give softness to the bread

Answer

(B) Evolution of CO2 makes the bread spongy

#22 MCQ 1M ▦ 1

Question

Match the following organisms with the products they produce.

Column I

ColumnII

a

Lactobacillus

i

Cheese

b

Saccharomyces cerevisiae

ii

Curd

c

Aspergillus niger

iii

Citric Acid

d

Acetobacter aceti

iv

Bread

v

Acetic Acid

Options

  1. (A) a – ii, b – iv, c – v, d – iii
  2. (B) a – ii, b – iv, c – v, d – i
  3. (C) a – iii, b – iv, c – iii, d – v
  4. (D) a – ii, b – iv, c – iii, d – v

Answer

(D) a – ii, b – iv, c – iii, d – v

#23 MCQ 1M

Question

Which of the following organic acid was produced by fermentation?

Options

  1. (A) Oxalic acid
  2. (B) Lactic acid
  3. (C) Citric acid
  4. (D) Propionic acid

Answer

(B) Lactic acid

#24 MCQ 1M

Question

The starter of inoculum is added to fresh milk in order to convert milk in curd. The term starter or inoculum here refers to

Options

  1. (A) Bacteria rich in vitamin B12
  2. (B) Bacteria rich in protein
  3. (C) Millions of LAB
  4. (D) All of the above

Answer

(C) Millions of LAB

#25 MCQ 1M

Question

The Roquefort cheese are ripened by growing a _______ on them, which gives them a particular flavour.

Options

  1. (A) Fungi
  2. (B) Virus
  3. (C) Bacteria
  4. (D) Algae

Answer

(A) Fungi

#26 MCQ 1M

Question

From the options given below what increases vitamin B12 in our stomach and plays a very beneficial role in checking disease causing microbes?

Options

  1. (A) Antibiotic
  2. (B) Lactic acid bacteria
  3. (C) Saccharomyces cerevisiae
  4. (D) Aspergillus niger

Answer

(B) Lactic acid bacteria

#27 MCQ 1M

Question

Choose the correct sentences.
(i) Dosa and idli are fermented by yeast.
(ii) Saccharomyces cerevisiae is a yeast
(iii) LAB increase quality of vitamin B12 in curd
(iv) Whisky and brandy are fermented beverages which are produced without distillation

Options

  1. (A) ii, iii, iv
  2. (B) ii, iii
  3. (C) i, ii, iii
  4. (D) i, iii, iv

Answer

(C) i, ii, iii

#28 MCQ 1M

Question

Yeast have been used for the commercial production of I. ethanol II. bread III. Incilage choose the correct option.

Options

  1. (A) I and II
  2. (B) I and III
  3. (C) I, II and III
  4. (D) None of these

Answer

(A) I and II

#29 MCQ 1M

Question

Conversion of milk to curd improves its nutritional value by increasing the amount of:

Options

  1. (A) Vitamin E
  2. (B) Vitamin D
  3. (C) Vitamin B12
  4. (D) Vitamin A

Answer

(C) Vitamin B12

#30 MCQ 1M

Question

The large holes in Swiss cheese are due to production of a large amount of ___ a ___by a bacterium ___ b ___ here a and b refers to

Options

  1. (A) a-CO2, b-Penicillium roqueforti
  2. (B) a-CO2, b-Propionibacterium sharmanii
  3. (C) a-CO2, b-Penicillium notatum
  4. (D) a-CO2, b-Saccharomyces cerevisiae

Answer

(B) a-CO2, b-Propionibacterium sharmanii

#31 MCQ 1M

Question

Curdling of milk takes place by

Options

  1. (A) Streptococcus lactis
  2. (B) Streptococcus thermophilus
  3. (C) Lactobacillus lactis
  4. (D) All the above

Answer

(D) All the above

#32 MCQ 1M

Question

Which micro-organism is used in the formation of cheese ?

Options

  1. (A) Streptococcus
  2. (B) Aspergillus
  3. (C) Acetic acid bacteria
  4. (D) Lactic acid bacteria

Answer

(D) Lactic acid bacteria

#33 MCQ 1M

Question

Which of the following food items are produced through fermentation by the microorganisms?
(I) Idli (II) Dosa
(III) Toddy (IV) Cheese

Options

  1. (A) I, II and III
  2. (B) I, III and IV
  3. (C) II, III and IV
  4. (D) I, II, III and IV

Answer

(D) I, II, III and IV

#34 MCQ 1M

Question

It is responsible for citric acid formation.

Options

  1. (A) Acetobacter aceti
  2. (B) Aspergillus niger
  3. (C) Streptococcus
  4. (D) None of the above

Answer

(B) Aspergillus niger

#35 MCQ 1M

Question

Antibiotics are mostly obtained from

Options

  1. (A) Fungi
  2. (B) Actinomycetes
  3. (C) Cyanobacteria
  4. (D) Both (A) and (B)

Answer

(D) Both (A) and (B)

#36 MCQ 1M

Question

Streptokinase is synthesised by _______.

Options

  1. (A) Yeast
  2. (B) Virus
  3. (C) Bacteria
  4. (D) Algae

Answer

(C) Bacteria

#37 MCQ 1M ▦ 1

Question

Match column I with column II and select the correct option using the code given below.

Column I

Column II

A

Citric acid

i

Trichoderma

B

Cyclosporin A

ii

Clostridium

C

Statins

iii

Aspergillus

D

Butyric acid

iv

Monascus

Options

  1. (A) A –iii, B –i, C –ii, D –iv
  2. (B) A –iii, B –i, C –iv, D –ii
  3. (C) A –i, B –iv, C – iii, D –ii
  4. (D) A –iii, B –iv, C –i, D –ii

Answer

(B) A –iii, B –i, C –iv, D –ii

#38 MCQ 1M

Question

Ethanol is commercially produced through a particular species of

Options

  1. (A) Saccharomyces
  2. (B) Clostridium
  3. (C) Trichoderma
  4. (D) Aspergillus

Answer

(A) Saccharomyces

#39 MCQ 1M

Question

Identify the bacterial product.

Options

  1. (A) Cyclosporin - A
  2. (B) Citric Acid
  3. (C) Acetic acid
  4. (D) Drinks like ethanol

Answer

(C) Acetic acid

#40 MCQ 1M

Question

_______ is an antibiotic.

Options

  1. (A) Malic acid
  2. (B) Streptokinase
  3. (C) Penicillin
  4. (D) Statins

Answer

(C) Penicillin

#41 MCQ 1M

Question

Which one of the following is not a biofertiliser?

Options

  1. (A) Agrobacterium
  2. (B) Rhizobium
  3. (C) Nostoc
  4. (D) Mycorrhiza

Answer

(A) Agrobacterium

#42 MCQ 1M

Question

Which of the following is not an antibiotic?

Options

  1. (A) Griseofulvin
  2. (B) Cephalosporin
  3. (C) Citric acid
  4. (D) Streptomycin

Answer

(C) Citric acid

#43 MCQ 1M

Question

Name the statin produced by the yeast, which have been commercialized as blood cholesterol lowering agent.

Options

  1. (A) Trichoderma polysporum
  2. (B) Monascus purpureus
  3. (C) Streptococcus
  4. (D) Lactobacillus

Answer

(B) Monascus purpureus

#44 MCQ 1M

Question

Sir Alexander Fleming extracted penicillin from:

Options

  1. (A) Penicillium citrinum
  2. (B) Penicillium notatum
  3. (C) Penicillium chrysogenum
  4. (D) Bacillus brevis

Answer

(B) Penicillium notatum

#45 MCQ 1M

Question

Statins used as blood cholesterol lowering agents are extracted from :

Options

  1. (A) Algae
  2. (B) Yeast
  3. (C) Virus
  4. (D) Bacteria

Answer

(B) Yeast

#46 MCQ 1M ▦ 1

Question

Which of the following is wrongly matched in the given table?

Microbe

Product

Application

(a)

Streptococcus

Streptokinase

Removal of clot from blood vessel

(b)

Clostridium
butyricum

Lipase

Removal of oil stains

(c)

Trichoderma polysporum

Cyclosporin A

Immunosuppressive drug

(d)

Monacus purpureus

Statins

Lowering of blood cholesterol

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(B) A and R both are correct, but R is not correct explanation of A.

#47 MCQ 1M

Question

Wine is prepared by fermentation of

Options

  1. (A) Bacillus liquefaciens
  2. (B) Penicillium roqueforti
  3. (C) Saccharomyces cerevisiae
  4. (D) Streptococcus aureus

Answer

(C) Saccharomyces cerevisiae

#48 MCQ 1M

Question

Cyclosporin A, used as immunosuppressive agent, is produced from

Options

  1. (A) Trichoderma polysporum
  2. (B) Monascus purpureus
  3. (C) Saccharomyces cerevisiae
  4. (D) Penicillium notatum

Answer

(A) Trichoderma polysporum

#49 MCQ 1M

Question

Which of the following is a commercial blood cholesterol lowering agent ?

Options

  1. (A) Cyclosporin A
  2. (B) Statin
  3. (C) Streptokinase
  4. (D) Lipases

Answer

(B) Statin

#50 MCQ 1M

Question

Identify the fungi.

Options

  1. (A) Aspergillus niger
  2. (B) Acetobacter aceti
  3. (C) Clostridium butyricum
  4. (D) Lactobacillus

Answer

(A) Aspergillus niger

#51 MCQ 1M

Question

Yeast is used in the production of

Options

  1. (A) Ethyl alcohol (ethanol)
  2. (B) Acetic acid
  3. (C) Cheese
  4. (D) Curd

Answer

(A) Ethyl alcohol (ethanol)

#52 MCQ 1M

Question

The organism used for alcohol fermentation is

Options

  1. (A) Penicillium
  2. (B) Pseudomonas
  3. (C) Aspergillus
  4. (D) Saccharomyces

Answer

(D) Saccharomyces

#53 MCQ 1M

Question

Secondary sewage treatment is mainly a

Options

  1. (A) physical process
  2. (B) mechanical process
  3. (C) chemical process
  4. (D) biological process

Answer

(D) biological process

#54 MCQ 1M

Question

Choose the correct pair

Options

  1. (A) Yeast - Ethanol production
  2. (B) Trichoderma polysporum - statins
  3. (C) Monascus purpureus - cyclosporin - A
  4. (D) All are correct

Answer

(A) Yeast - Ethanol production

#55 MCQ 1M

Question

First antibiotic isolated was

Options

  1. (A) Terramycin
  2. (B) Neomycin
  3. (C) Penicillin
  4. (D) Streptomycin

Answer

(C) Penicillin

#56 MCQ 1M

Question

_______ are produced without distillation.

Options

  1. (A) Whiskey and rum
  2. (B) Rum and wine
  3. (C) Beer and whisky
  4. (D) Wine and beer

Answer

(D) Wine and beer

#57 MCQ 1M

Question

Identify the correct pair :

Options

  1. (A) Aspergillus niger - Fungi - Ethanol
  2. (B) Monascus purpureus - Bacteria - Statins
  3. (C) Trichoderma polysporum - Fungi-Cyclosporin A
  4. (D) Saccharomyces cerevisiae - Bacteria - Ethanol

Answer

(C) Trichoderma polysporum - Fungi-Cyclosporin A

#58 MCQ 1M

Question

Azolla is used as a biofertiliser because it

Options

  1. (A) Has association of mycorrhiza
  2. (B) Multiplies at faster rate to produce massive biomass
  3. (C) Has association of nitrogen-fixing Rhizobium
  4. (D) Has association of nitrogen-fixing cyanobacteria

Answer

(D) Has association of nitrogen-fixing cyanobacteria

#59 MCQ 1M

Question

For the commercial and industrial production of Citric Acid, which of the following microbes is used?

Options

  1. (A) Clostridium butyricum
  2. (B) Aspergillus niger
  3. (C) Lactobacillus sp
  4. (D) Saccharomyces cerevisiae

Answer

(B) Aspergillus niger

#60 MCQ 1M

Question

What was discovered by Alexander Fleming ?

Options

  1. (A) Staphylococcus
  2. (B) Penicillium
  3. (C) Lactobacillus
  4. (D) Acetic acid

Answer

(B) Penicillium

#61 MCQ 1M

Question

_______ are used in detergent formulations and are helpful in removing oily stains from the laundry.

Options

  1. (A) Cyclosporin - A
  2. (B) Penicillium notatum
  3. (C) Ethanol
  4. (D) Lipases

Answer

(D) Lipases

#62 MCQ 1M

Question

Monascus purpureus is a yeast used commercially in the production of

Options

  1. (A) ethanol
  2. (B) streptokinase for removing dots from the blood vessels
  3. (C) citric acid
  4. (D) statins - Blood cholesterol lowering agent

Answer

(D) statins - Blood cholesterol lowering agent

#63 MCQ 1M

Question

Which of the following organism is useful in the preparation of Roquefort cheese?

Options

  1. (A) Mucor
  2. (B) Rhizopus
  3. (C) Aspergillus
  4. (D) Penicillium

Answer

(D) Penicillium

#64 MCQ 1M ▦ 1

Question

Match list I with list II
Choose the correct answer from the options given below.

List I

List II

A

Aspergillus niger

i

Acetic Acid

B

Acetobacter aceti

ii

Lactic Acid

C

Clostridium butyricum

iii

Citric Acid

D

Lactobacillus

iv

Butyric Acid

Options

  1. (A) A – iii, B – i, C – iv, D – ii
  2. (B) A – i, B – ii, C – iii, D – iv
  3. (C) A – ii, B – iii, C – i, D – iv
  4. (D) A – iv, V – ii, C – i, D – iii

Answer

(A) A – iii, B – i, C – iv, D – ii

#65 MCQ 1M

Question

Yeast has been used for the commercial production of I. ethanol II. bread III. Toddy drink IV. Biogas. Choose the correct option.

Options

  1. (A) I and II
  2. (B) I and III
  3. (C) I, II and III
  4. (D) IV

Answer

(A) I and II

#66 MCQ 1M

Question

What is used as an immunosuppressive agent in organ transplant?

Options

  1. (A) Cyclosporin - A
  2. (B) Statin
  3. (C) Penicillium
  4. (D) Protease

Answer

(A) Cyclosporin - A

#67 MCQ 1M

Question

Which of the following is correctly matched for the product produced by them?

Options

  1. (A) Methanobacterium : Lactic acid
  2. (B) Penicillium notatum : Acetic acid
  3. (C) Saccharomyces cerevisiae : Ethanol
  4. (D) Acetobacter aceti : Antibiotics

Answer

(C) Saccharomyces cerevisiae : Ethanol

#68 MCQ 1M ▦ 1

Question

Match the following columns and select the correct option.

Column I

Column II

a

Clostridium butyricum

i

Cyclosporin - A

b

Trichoderma

polysporum

ii

Butyric acid

c

Monascus purpureus

iii

Citric acid

d

Aspergillus niger

iv

Blood cholesterol lowering agent

Options

  1. (A) a – iv, b – iii, c – ii, d – i
  2. (B) a – iii, b – iv, c – ii, d – i
  3. (C) a – ii, b – i, c – iv, d – iii
  4. (D) a – i, b – ii, c – iv, d – iii

Answer

(C) a – ii, b – i, c – iv, d – iii

#69 MCQ 1M

Question

Penicillium notatum stops the growth of

Options

  1. (A) Aspergillus niger
  2. (B) Trichoderma polysporum
  3. (C) Monascus purpureus
  4. (D) Staphylococci (Bacteria)

Answer

(D) Staphylococci (Bacteria)

#70 MCQ 1M

Question

Primary treatment is the

Options

  1. (A)
    Physical removal of large and small particles from sewage
  2. (B)
    Biological removal of large and small particles from sewage
  3. (C) Both (A) and (B)
  4. (D) Chemical removal of large and small particles from sewage

Answer

(A)

Physical removal of large and small particles from sewage

#71 MCQ 1M

Question

In a pond, if there is too much wastage, then the BOD of the pond will

Options

  1. (A) Increase
  2. (B) Decrease
  3. (C) Remain same
  4. (D) Both (A) and (B)

Answer

(A) Increase

#72 MCQ 1M

Question

The domestic sewage in large cities.

Options

  1. (A) has a high BOD as it contains both aerobic and anaerobic bacteria
  2. (B) is processed by aerobic and then anaerobic bacteria in the secondary treatment in sewage treatment plants (STPs)
  3. (C) when treated in STPs does not really require the aeration step as the sewage contains adequate oxygen.
  4. (D) has very high amount of suspended solids and dissolved salts.

Answer

(B) is processed by aerobic and then anaerobic bacteria in the secondary treatment in sewage treatment plants (STPs)

#73 MCQ 1M

Question

Activated sludge means :

Options

  1. (A) Sedimented flocs
  2. (B) Aerobic bacteria
  3. (C) Inaerobic bacteria
  4. (D) Primary sludge

Answer

(A) Sedimented flocs

#74 MCQ 1M

Question

A nitrogen fixing microbe associated with Azolla in rice field is

Options

  1. (A) Spirulina
  2. (B) Anabaena
  3. (C) Frankia
  4. (D) Tolypothrix

Answer

(B) Anabaena

#75 MCQ 1M

Question

Which of the following is put into Anaerobic sludge digester for further sewage treatment?

Options

  1. (A) Activated sludge
  2. (B) Primary sludge
  3. (C) Floating debris
  4. (D) Effluents of primary treatment

Answer

(A) Activated sludge

#76 MCQ 1M

Question

A : STP purify sewage
R : In the end of STP, the water possess flocs.

Options

  1. (A) A and R both are correct
  2. (B) A and R both are incorrect
  3. (C) A is incorrect, R is correct
  4. (D) A is correct, R is incorrect

Answer

(D) A is correct, R is incorrect

#77 MCQ 1M

Question

Organisms called methanogens are most abundant in a

Options

  1. (A) Sulphur rock
  2. (B) Cattle yard
  3. (C) Polluted steam
  4. (D) Hot spring

Answer

(B) Cattle yard

#78 MCQ 1M

Question

Which of the following organisations have developed technology for biogas production?

Options

  1. (A) TARI and ICZN
  2. (B) ICBN and KVIC
  3. (C) IRRI and IARI
  4. (D) KVIC and IARI

Answer

(D) KVIC and IARI

#79 MCQ 1M

Question

Which of the following statements about methanogens is not correct?

Options

  1. (A) They can be used to produce biogas
  2. (B) They are found in the rumen of cattle and their excreta
  3. (C) They grow aerobically and breakdown cellulose rich food
  4. (D) They produce methane gas

Answer

(C) They grow aerobically and breakdown cellulose rich food

#80 MCQ 1M

Question

The guts of cow and buffalo possess

Options

  1. (A) Methanogens
  2. (B) Cyanobacteria
  3. (C) Fucus sp.
  4. (D) Chlorella sp.

Answer

(A) Methanogens

#81 MCQ 1M

Question

If bacteria grow on cellulosic material, they produce large amount of which gas ?

Options

  1. (A) Ethane
  2. (B) Oxygen
  3. (C) Methane
  4. (D) Propane

Answer

(C) Methane

#82 MCQ 1M

Question

Methanogens found in

Options

  1. (A) Biogas plant
  2. (B) Rumen of cattle
  3. (C) and (B) are correct
  4. (D) and (B) are incorrect

Answer

(C) and (B) are correct

#83 MCQ 1M

Question

Which is correct group of gases for anaerobic digestion ?

Options

  1. (A) Carbon dioxide, hydrogen sulphide, methane, ethane.
  2. (B) Methane, oxygen, carbon dioxide
  3. (C) Methane, hydrogen sulphide, carbon dioxide
  4. (D) Ethane, methane, hydrogen sulphide

Answer

(C) Methane, hydrogen sulphide, carbon dioxide

#84 MCQ 1M

Question

Bt cotton is used to destroy

Options

  1. (A) Caterpillar of butterfly
  2. (B) Cockroach alimentary canal
  3. (C) Aschleminthes
  4. (D) Mosquito's intestine

Answer

(A) Caterpillar of butterfly

#85 MCQ 1M

Question

Which is a microbial insecticide?

Options

  1. (A) Bacillus thuringiensis
  2. (B) Bacillus subtilis
  3. (C) Bacillus polymixa
  4. (D) Bacillus brevis

Answer

(A) Bacillus thuringiensis

#86 MCQ 1M

Question

Which of the following fungus produces cyclosporin A which is used as an immunos uppressive agent in organ - transplant patients?

Options

  1. (A) Alternaria
  2. (B) Neurospora
  3. (C) Trichoderma
  4. (D) Puccinia

Answer

(C) Trichoderma

#87 MCQ 1M

Question

Trichoderma are _______.

Options

  1. (A) Symbotic algae
  2. (B) Photosynthetic
  3. (C) Symbiotic fungi
  4. (D) free-living fungi

Answer

(D) free-living fungi

#88 MCQ 1M

Question

The phenomenon of using a predator for controlling a pest is

Options

  1. (A) Biological control
  2. (B) Genetic engineering
  3. (C) Artificial control
  4. (D) Confusion technique

Answer

(A) Biological control

#89 MCQ 1M

Question

Genus of Baculo virus is

Options

  1. (A) Retrovirus
  2. (B) Nucleopolyhedrovirus
  3. (C) TMV
  4. (D) Adenovirus

Answer

(B) Nucleopolyhedrovirus

#90 MCQ 1M

Question

The organism which is useful to produce chemical which inhibit immunity during organ transplant.

Options

  1. (A) Streptococcus
  2. (B) Monascus purpureus
  3. (C) Lactobacillus
  4. (D) Trichoderma polysporum

Answer

(D) Trichoderma polysporum

#91 MCQ 1M

Question

Microbe used for biocontrol of pest butterfly caterpillar is

Options

  1. (A) Saccharomyces cerevisiae
  2. (B) Bacillus thuringiensis
  3. (C) Streptococcus sp.
  4. (D) Trichoderma sp.

Answer

(B) Bacillus thuringiensis

#92 MCQ 1M

Question

A common biocontrol agent for the control of plant diseases is

Options

  1. (A) Baculovirus
  2. (B) Bacillus thuringiensis
  3. (C) Glomus
  4. (D) Trichoderma

Answer

(D) Trichoderma

#93 MCQ 1M

Question

When a natural predator is applied on the other pathogenic organisms to control them, this process is called.

Options

  1. (A) Biological control
  2. (B) Genetic engineering
  3. (C) Confusion technique
  4. (D) Artificial control

Answer

(A) Biological control

#94 MCQ 1M

Question

Latest trend in plant disease control is

Options

  1. (A) Chemical control
  2. (B) Biological control
  3. (C) Good manure and fertilizer
  4. (D) Breeding for disease resistance

Answer

(B) Biological control

#95 MCQ 1M

Question

Biopesticides include

Options

  1. (A) Bioherbicides
  2. (B) Bioinsecticides
  3. (C) Bioherbicides and bioinsecticides
  4. (D) Bioherbicides, bioinsecticides and biofertilizers

Answer

(C) Bioherbicides and bioinsecticides

#96 MCQ 1M

Question

Biofertilizers include

Options

  1. (A) Nitrogen fixing bacteria
  2. (B) Nitrogen fixing cyanobacteria
  3. (C) Both bacteria and cyanobacteria
  4. (D) Bacteria, cyanobactria and mycorrhizal fungi

Answer

(D) Bacteria, cyanobactria and mycorrhizal fungi

#97 MCQ 1M

Question

Which one is a nonsymbiotic nitrogen fixer?

Options

  1. (A) Rhizobium
  2. (B) Oscillatoria
  3. (C) Nostoc
  4. (D) Lactobacillus

Answer

(D) Lactobacillus

#98 MCQ 1M

Question

Aquatic fern which is an excellent biofertilizer.

Options

  1. (A) Salvinia
  2. (B) Azolla
  3. (C) Marsilea (C) Chlorella sp.

Answer

(B) Azolla

#99 MCQ 1M

Question

Which of the following is free living aerobic and nonphotosynthetic nitrogen fixing bacterium?

Options

  1. (A) Rhizobium
  2. (B) Nostoc
  3. (C) Azospirillum
  4. (D) Azotobacter

Answer

(D) Azotobacter

#100 MCQ 1M

Question

Select the mismatch.

Options

  1. (A) Rhodospirillum - Mycorrhiza
  2. (B) Anabaena - Nitrogen fixer
  3. (C) Rhizobium-Alfalfa
  4. (D) Frankia-Alnus

Answer

(A) Rhodospirillum - Mycorrhiza

#101 MCQ 1M

Question

What is required for nitrogen fixation by Rhizobium?

Options

  1. (A) Potassium
  2. (B) Phosphorus
  3. (C) Nitrate
  4. (D) Sodium

Answer

(C) Nitrate

#102 MCQ 1M

Question

Azolla enriches rice fields with nitrogen due to its association with

Options

  1. (A) Anabaena
  2. (B) Nostoc
  3. (C) Rhizobium
  4. (D) Frankia

Answer

(A) Anabaena

#103 MCQ 1M

Question

Among the following pairs of microbes, which pair has both the microbes that can be used as biofertilizers?

Options

  1. (A) Aspergillus and Rhizopus
  2. (B) Rhizobium and Rhizopus
  3. (C) Cyanobacteria and Rhizobium
  4. (D) Aspergillus and Cyanobacteria

Answer

(C) Cyanobacteria and Rhizobium

#104 MCQ 1M

Question

Symbiotic nitrogen fixation in root nodules of some legumes is caused by

Options

  1. (A) Nitrosomonas
  2. (B) Rhizobium
  3. (C) Azotobacter
  4. (D) Nitrobacter

Answer

(B) Rhizobium

#105 MCQ 1M

Question

Most famous nitrogen fixing bacterium/biofertilizer is

Options

  1. (A) Nitrobacter
  2. (B) Nitrosomonas
  3. (C) Nitrococcus
  4. (D) Rhizobium

Answer

(D) Rhizobium

#106 MCQ 1M

Question

Mycorrhiza is helpful in

Options

  1. (A) Synthesis of food
  2. (B) Getting nutrients from soil
  3. (C) Providing resistance against different regulators
  4. (D) Increase the fertility of soil

Answer

(B) Getting nutrients from soil

#107 MCQ 1M

Question

Rhizosphere is the region where

Options

  1. (A) Rhizobium forms root nodules
  2. (B) Algae and root make contact
  3. (C) Soil and root make contact
  4. (D) Bacterial and root nearly make contact

Answer

(D) Bacterial and root nearly make contact

#108 MCQ 1M

Question

The common nitrogen fixer in paddy fields is

Options

  1. (A) Rhizobium
  2. (B) Azospirillum
  3. (C) Oscillatoria
  4. (D) Frankia

Answer

(C) Oscillatoria

#109 MCQ 1M

Question

A nitrogen fixing bacterium that forms a loose association with the roots of plants is

Options

  1. (A) Azotobacter
  2. (B) Bacillus polymyxa
  3. (C) Clostridium
  4. (D) Azospirillum

Answer

(D) Azospirillum

#110 MCQ 1M

Question

Biofertilizers

Options

  1. (A) Kill pests
  2. (B) Prevent pest growth
  3. (C) Retain soil fertility
  4. (D) All of the above

Answer

(C) Retain soil fertility

#111 MCQ 1M

Question

What is correct about nitrogen fixation by legumes? They fix nitrogen through

Options

  1. (A) Specialised bacteria in their roots
  2. (B) Specialised bacteria in their leaves
  3. (C) Independent of bacteria that live in their roots
  4. (D) The statement is wrong

Answer

(A) Specialised bacteria in their roots

#112 MCQ 1M

Question

If wheat field is inoculated with Rhizobium

Options

  1. (A) Soil will become nitrogen rich
  2. (B) No effect on soil nitrogen
  3. (C) Soil will be depleted of nitrogen
  4. (D) Soil will become rich in calcium

Answer

(B) No effect on soil nitrogen

#113 MCQ 1M

Question

Some blue green algae can be used as biofertilizer as they are

Options

  1. (A) Photosynthetic
  2. (B) Surrounded by mucilage
  3. (C) Growing every where
  4. (D) Capable of fixing nitrogen

Answer

(D) Capable of fixing nitrogen

#114 MCQ 1M

Question

Biofertilizers include

Options

  1. (A) Cow dung manure and farmyard waste
  2. (B) A quick growing crop ploughed back
  3. (C) BGA Anabaena and Azolla
  4. (D) All the above

Answer

(C) BGA Anabaena and Azolla

#115 MCQ 1M

Question

Which of the following can use molecular nitrogen as nutrient?

Options

  1. (A) Methanomonas
  2. (B) Mucor
  3. (C) Rhizobium
  4. (D) Spirogyra

Answer

(C) Rhizobium

#116 MCQ 1M

Question

The nitrogen fixing symbiotic organism present in Azolla is

Options

  1. (A) Nostoc
  2. (B) Anabaena
  3. (C) Aulosira
  4. (D) Azospirillum

Answer

(B) Anabaena

#117 MCQ 1M

Question

What adds organic matter to the soil and increase its fertility?

Options

  1. (A) Pseudomonas
  2. (B) Blue green algae
  3. (C) Baculo virus
  4. (D) LAB

Answer

(B) Blue green algae

#118 MCQ 1M

Question

They are mostly used in organic fertilizer.

Options

  1. (A) Bacteria
  2. (B) Cyanobacteria
  3. (C) Fungi
  4. (D) All are correct

Answer

(D) All are correct

#119 MCQ 1M

Question

Which bacteria fix atmospheric nitrogen while they are free - living in the soil?

Options

  1. (A) Azotobacter
  2. (B) Rhizobium
  3. (C) Cyanobacteria
  4. (D) Anabaena

Answer

(A) Azotobacter

#120 MCQ 1M

Question

Mycorrhiza represents

Options

  1. (A) Antagonism
  2. (B) Endemism
  3. (C) Symbiosis
  4. (D) Parasitism

Answer

(C) Symbiosis

#121 MCQ 1M

Question

Due to which of the following organisms, yield of rice is increased?

Options

  1. (A) Anabaena
  2. (B) Bacillus popilliae
  3. (C) Sesbani
  4. (D) Bacillus polymena

Answer

(A) Anabaena

#122 MCQ 1M

Question

Assertion : LAB improves the Vit-B12 Quality
Reason : Lactobacillus produces lactic acid

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(B) A and R both are correct, but R is not correct explanation of A.

#123 MCQ 1M

Question

Assertion : Protease enzyme is produced by microbes.
Reason : Protease enzyme is used in removing oily stains from the laundry

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(C) A is correct, but R is wrong

#124 MCQ 1M

Question

Assertion : Cyclosporin-A is used as an immunosuppressive agent in organ transplant patients.
Reason : Cyclosporin-A is obtain from Trichoderma polysporum (yeast).

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(B) A and R both are correct, but R is not correct explanation of A.

#125 MCQ 1M

Question

Assertion : The excreta of cattle is rich in methanogens bacteria
Reason : Dung can be used in biogas

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(B) A and R both are correct, but R is not correct explanation of A.

#126 MCQ 1M

Question

Assertion : Bacillus thuringiensis is used in the Pest Control agent in agriculture
Reason : Certain genus of fungi is also used as pest control agent in agriculture

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(B) A and R both are correct, but R is not correct explanation of A.

#127 MCQ 1M

Question

Assertion : Cyclosporin-A is used during organ transplant in patient
Reason : It lowers down blood cholesterol level

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(C) A is correct, but R is wrong

#128 MCQ 1M

Question

Assertion : LAB are used in bread making
Reason : Lactobacillus are used in curd making

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(D) A is wrong, but R is correct

#129 MCQ 1M

Question

Assertion : Instead of chemical pesticides, biological pest control are used
Reason : This is an equilibrium pest control.

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(B) A and R both are correct, but R is not correct explanation of A.

#130 MCQ 1M

Question

Assertion : Biological control destroy pest.
Reason : Pest have harmful effect on a crop leading decrease in productivity

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(B) A and R both are correct, but R is not correct explanation of A.

#131 MCQ 1M

Question

Assertion : An effective and pollution free farming can be achieved by use of organic fertilisers
Reason : Chemical fertilisers cause Pollution

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(C) A is correct, but R is wrong

#132 MCQ 1M

Question

Assertion : By the use of chemical process, the organic substances are used up in the sewage
Reason : Bacteria and other microbes utilized organic substances in the water.

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(C) A is correct, but R is wrong

#133 MCQ 1M

Question

Assertion : Cellulase enzyme is used in removing oily stains from the laundry
Reason : Streptokinase is used as a clot buster for removing clots from the blood vessels

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(D) A is wrong, but R is correct

#134 MCQ 1M

Question

Assertion : LAB are very important for digestive system
Reason : LAB also protects us from disease causing microbes.

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(A) A and R both are correct, and R is correct explanation of A.

#135 MCQ 1M

Question

Assertion : Yeasts such as Saccharomyces cerevisiae are used in baking industry.
Reason : Carbon dioxide produced during fermentation causes bread dough to rise by thermal expansion.

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(A) A and R both are correct, and R is correct explanation of A.

#136 MCQ 1M

Question

Assertion : BOD is a measure of the organic matter present in the water.
Reason : The lower the BOD of water, lower is its polluting potentials.

Options

  1. (A) A and R both are correct, and R is correct explanation of A.
  2. (B) A and R both are correct, but R is not correct explanation of A.
  3. (C) A is correct, but R is wrong
  4. (D) A is wrong, but R is correct

Answer

(A) A and R both are correct, and R is correct explanation of A.

#137 MCQ 1M 🖼 1

Question

Which gases are produced in labelled part X in given figure ?
Digester
X

Options

  1. (A) O2, CO, CO2, H2, CH4
  2. (B) CO2, O2, H2
  3. (C) CH4, H2, CO2, O2
  4. (D) CO2, H2, CH4

Answer

(D) CO2, H2, CH4

#138 MCQ 1M

Question

Choose the correct option for the given diagram from the following.
of respiratory disease
Tobacco mosaic disease
tumor disease

Options

  1. (A) Adenovirus - cause
  2. (B) Bacteriophage -
  3. (C) Viroid - Potato spindle
  4. (D) Prion - Alzheimer's disease

Answer

(A) Adenovirus - cause

S src: Case Study Base Questions And Answers match 66% type: 6 Q ⤓ Export ZIP
#1 CS

Question

Secondary treatment or Biological treatment : The primary effluent is passed into large aeration tanks where it is constantly agitated mechanically and air is pumped into it. This allows vigorous growth of useful aerobic microbes into Flocs (masses of bacteria associated with fungal filaments to form mesh like structures).
While growing, these microbes consume the major part of the organic matter in the effluent. This significantly reduces the BOD (Biochemical Oxygen Demand) of the effluent. BOD refers to the amount of the oxygen that would be consumed if all the organic matter in one liter of water were oxidised by bacteria.
The sewage water is treated till the BOD is reduced. The BOD test measures the rate of uptake of oxygen by microorganisms in a sample of water and thus, indirectly, BOD is a measure of organic matter present in the water. The greater the BOD of waste water, more is its polluting potential.
(i) Which part is carried forward to secondary treatment after primary treatment?
(ii) Expand the acronym BOD.
(iii) What is the relationship between BOD and DO?
(iv) What are flocs?

Answer

(i) The effluent from the primary settling tank is forward for secondary treatment.
(ii) BOD - Biochemical Oxygen Demand
(iii) BOD is a measure of the oxygen required by the bacteria for oxidation or organic matter present in the water. Where as DO is a amount of dissolved oxygen in the water. Both are inversely proportion to each other.
(iv) Flocs are the masses of bacteria associated with fungal filaments to form mesh like structures.
#2 CS

Question

Methanogens
Biogas is a mixture of gases such as carbon dioxide and methane and H2. It has predominantly gas is methane about 60%. The technology of biogas production was developed in India mainly due to the efforts of Indian Agricultural Research Institute (IARI) and Khadi and Village Industries Commission (KVIC).
Bacteria are collectively called methanogens, that act on cattle dung. and one such common bacterium is Methanobacterium. These bacteria are commonly found in the anaerobic sludge during sewage treatment. These bacteria are also present in the rumen (a part of stomach) of cattle.
Cattle dung is available in large quantities in rural areas where cattle are used for a variety of purposes. So biogas plants are more often built in rural areas.
(i) What is biogas?
(ii) Which organisation developed biogas technology?
(iii) Which bacteria play significant role in the production of biogas?
(iv) Where is the spent slurry used?

Answer

(i) Biogas contains mixture of gases such as methane, hydrogen sulphide and carbon dioxide.
(ii) The technology of biogas production was developed in India mainly due to the efforts of Indian Agricultural Research Institute (IARI) and Khadi and Village Industries Commission (KVIC).
(iii) Methanogens
(iv) The spent slurry is used as fertiliser.
#3 CS

Question

Alexander Fleming
Antibiotics produced by microbes are regarded as one of the most significant discoveries of the twentieth century and have greatly contributed towards the welfare of the human society.
Alexander Fleming while working on Staphylococci bacteria, once observed a mould growing in one of his unwashed culture plates around which Staphylococci could not grow. He found out that it was due to a chemical produced by the mould and he named it Penicillin after the mould Penicillium notatum.
However, its full potential as an effective antibiotic was established much later by Ernest Chain and Howard Florey. After Penicillin, other antibiotics were also purified from other microbes. Antibiotics have greatly improved our capacity to treat deadly diseases such as plague, whooping cough (kali khansi), diphtheria (gal ghotu) and leprosy (kusht rog), which used to kill millions all over the globe.
(i) Who discovered antibiotic?
(ii) Which mould is grown with Staphylococcus during the experiment performed by Alexander?
(iii) Who established full potential of antibiotic penicillin?
(iv) Which other diseases can be treated by antibiotic?

Answer

(i) Alexander Fleming
(ii) Penicillium notatum
(iii) Ernest Chain and Howard Florey
(iv) Plague, whooping cough, diphtheria, leprosy etc.
#4 CS

Question

Nitrogen fixing bacteria
We have now realised that there are problems associated with the overuse of chemical fertilisers and there is a large pressure to switch to organic farming – the use of biofertilisers. Biofertilisers are organisms that enrich the nutrient quality of the soil.
The main sources of biofertilisers are bacteria, fungi and cyanobacteria. the nodules on the roots of leguminous plants formed by the symbiotic association of Rhizobium. These bacteria fix atmospheric nitrogen into organic forms, which is used by the plant as nutrient.
Other bacteria that can fix atmospheric nitrogen while free-living in the soil are Azospirillum and Azotobacter, thus enriching the nitrogen content of the soil. Mycorrhiza also play significant role for the plants. Anabaena, Nostoc and Oscillatoria also makes soil nitrogen rich.
(i) Why is organic fertiliser equired?
(ii) Name the Cyanobacteria involved in nitrogen fixation.
(iii) Which bacteria is found in the symbiotic association with roots of leguminous plants?
(iv) Which are the free living nitrogen fixing bacteria?

Answer

(i) Chemical fertilisers are polluting land and water, while biological fertilisers are easily available, non-polluting and economical.
(ii) Anabaena, Nostoc and Oscillatoria
(iii) Rhizobium
(iv) Azospirillum and Azotobacter
#5 CS 🖼 1

Question

People of a village in Gujarat are setting up a biogas plant to equip their village with renewable energy. As per the diagram, a mixture of cow dung and water is put in a digestion tank. In the anaerobic condition of a digestion tank, microorganisms decompose the organic matter. This process mainly produces gases like methane (CH4) and carbon dioxide (CO2). The biogas plant has an outlet, which is connected to a pipe to supply biogas to nearby houses. The semi-liquid material remaining after digestion comes out as sludge, which is an excellent natural fertilizer for agriculture.
(i) What is the main reason for adding a mixture of manure and water to the digestion tank according to the diagram?
(a) Increase oxygen supply
(b) To provide a suitable medium for the digestion process of microorganisms
(c) To keep the gas cool
(d) To separate sludge
(ii) Which gas is mainly stored in the gas holder shown in the figure?
(a) Carbon dioxide (CO2)
(b) Oxygen (O2)
(c) Methane (CH4)
(d) Nitrogen (N2)
(iii) What type of digestion process takes place in the digestion tank shown in the figure?
(a) Process which takes place in the presence of oxygen
(b) Process due to lack of oxygen
(c) Process based on light
(d) Chemical combustion process
(iv) According to the figure, for what purpose is the sludge produced after digestion mainly useful?
(a) As fuel
(b) As industrial waste
(c) As a manure
(d) Produce gas again

Answer

(i) (b) To provide a suitable medium for the digestion process of microorganisms
(ii) (c) Methane (CH4)
(iii) (b) Process due to lack of oxygen
(iv) (c) As a manure
#6 CS

Question

A progressive group of farmers from Gujarat decided to adopt eco-friendly farming. The continuous use of chemical pesticides was reducing the fertility of the soil and destroying the beneficial flora. So they adopted biocontrol methods. To control harmful insects in the field, they used Bacillus thuringiensis (Bt), which destroys the larvae of certain types of insects.
To protect crop against fungal diseases. Trichoderma fungus was used, which suppresses the growth of pathogenic fungi, for pest control, NPV (Nucleo Polyhedro Virus) was used, which is a virus of the Baculovirus group and affects only specific target pests.
In addition, natural control of harmful insects like aphids was achieved by using ladybird insects in cotton and vegetable fields. All these biocontrol methods increased crop production and had no harmful effects on the environment and other beneficial organisms.
(i) According to the above case study, what is the main effect of Bacillus thuringiensis (Bt)?
(a) At the roots of plants
(b) On insects larvae
(c) On bacteria present in the soil
(d) On fungal diseases
(ii) For what purpose is Trichoderma mainly used?
(a) As an insecticides
(b) As a virucide
(c) As biocontrol against pathogenic fungi
(d) As fertilisers
(iii) What is true for NPV (Baculovirus) mentioned in the case study?
(a) It destroys all living things
(b) It affects only target pests
(c) It is a chemical poison
(d) It reduces the fertility of soil
(iv) Ladybird is an example of which type of pest control.
(a) Chemical control
(b) Physical control
(c) Biocontrol by natural enemies
(d) Mechanical control

Answer

(i) (b) On insect larvae
(ii) (c) As biocontrol against pathogenic fungi
(iii) (b) It affects only target pests
(iv) (c) Biocontrol by natural enemies

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