1. Which one thing is not true about antibiotics?
(a) The term ―antibiotic‖ was coined by Selman Waksman in 1942
(b) First antibiotic was discovered by Alexander Flemming
(c) Each antibiotic is effective only against one particular kind of germ
(d) Some persons can be allergic to a particular antibiotic
2. Which of the following is likely to be achieved in the coming two decades?
(a) A complete understanding of the brainmindinteraction
(b) Control of cancer
(c) Correction of genetic basis of diabetes mellitus
(d) Production of biodegradable plastic rather than cellulose by higher plants
3. Gobar gas contains mainly
(a) CH4 + CO2
(b) CH4 + O2
(c) CO2 + H2
(d) CO2 + SO2
4. Which one of the following is nonsymbioticbiofertilizer?
(a) Azotobacter
(b) Anabaena
(c) Rhizobium
(d) VAM.
5. Farmers have reported over 50% higher yields of rice by using the biofertilizer
(a) Azollapinnata
(b) Cyanobacteria
(c) Legume-Rhizobium symbiosis
(d) Mycorrhiza
6. The aquatic fern, which is an excellent biofertiliseris
(a) Azolla
(b) Salvinia
(c) Marsilia
(d) Pteridium
7. Which of the following is pair of biofertilizers?
(a) Azolla and BGA
(b) Nostoc and legumes
(c) Rhizobium and grasses
(d) Salmonella and E. coli
8. Two microbes found to be very useful in genetic engineering are
(a) Vibrio cholera and a tailed bacteriophage
(b) Diplococcus sp. and Pseudomonas sp.
(c) Crow gall bacterium and Caenorhabditis elegans
(d) Escherichia coli and Agrobacterium
9. Probiotics are
(a) cancer inducing microbes
(b) new kind of food allergens
(c) live microbial food supplement
(d) safe antibiotics
10. Which one of the following pairs is wrongly matched?
(a) Yeast – ethanol
(b) Streptomycetes – antibiotic
(c) Coliforms – vinegar
(d) Methanogens – gobar gas.
11. Trichoderma harzianum has proved a useful microorganism for
(a) bioremediation of contaminated soils
(b) reclamation of wastelands
(c) gene transfer in higher plants
(d) biological control of soil-borne plant pathogens
12. Human insulin is being commercially produced from a transgenic species of
(a) Escherichia
(b) Mycobacterium
(c) Rhizobium
(d) Saccharomyces
13. Cryl endotoxins obtained from Bacillus thuringiensis are effective against
(a) mosquitoes
(b) flies
(c) nematodes
(d) boll worms
14. A common biocontrol agent for the control of plant diseases is
(a) Baculovirus
(b) Bacillus thuringiensis
(c) Glomus
(d) Trichoderma
15. The common nitrogen fixer in paddy fields is
(a) Rhizobium
(b) Azospirillum
(c) Oscillatoria
(d) Frankia
16. Which one of the following is not used in organic farming?
(a) Glomus
(b) Earthworm
(c) Oscillatoria
(d) Snail
17. An organism used as a biofertilizer for raising soyabean crops is
(a) Azotobacter
(b) Azospirillum
(c) Rhizobium
(d) Nostoc
18. Which one of the following help in absorption of phosphorus from soil by plants?
(a) Glomus
(b) Rhizobium
(c) Frankia
(d) Anabaena
19. Read the following statement having two blanks (A and B): ―A drug used for — —– (A) ——– patients is obtained from a species of the organism ——– (B) ——–.‖ The one correct option for the two blanks is Blank – A Blank – B
(a) Heart — Penicillium
(b) Organ-transplant — Trichoderma
(c) Swine flu — Monascus
(d) AIDS — Pseudomonas
20. Which one of the following is a wrong matching of a microbe and its industrial product, while the remaining three are correct?
(a) Yeast – statins
(b) Acetobacteraceti – acid
(c) Clostridium butylicum – lactic acid
(d) Aspergillus niger – citric acid
21. Monascuspurpureus is a yeast used commercially in the production of:
(a) ethanol
(b) streptokinase for removing clots from the blood vessels.
(c) Citric acid
(d) blood cholesterol lowering statins
22. A patient brought to a hospital with myocardial infarction is normally immediately given:
(a) Penicillin
(b) Streptokinase
(c) Cyclosporin-A
(d) Statins
23. Which one of the following microbes forms symbiotic association with plants and helps them in their nutrition
(a) Azotobacter
(b) Aspergillus
(c) Glomus
(d) Trichoderma
24. Yeast is used in the production of
(a) Citric acid and lactic acid
(b) Lipase and pectinase
(c) Bread and beer
(d) Cheese and butter
25. A nitrogen-fixing microbe associated with Azolla in rice fields is:
(a) Spirulina
(b) Anabaena
(c) Frankia
(d) Tolypothrix
26. Which one of the following is an example of carrying out biological control of pests/ diseases using microbes?
(a) Trichoderma sp. against certain plant pathogens
(b) Nucleopolyhedrovirus against white rust in Brassica
(c) Bt – cotton to increase cotton yield
(d) Lady bird beetle against aphids in mustard
27. Maximum nutritional diversity is found in the group.
(a) Fungi
(b) Animalia
(c) Monera
(d) Plantae
28. In gobar gas, the maximum amount is that of
(a) butane
(b) methane
(c) propane
(d) carbon dioxide
29. The domestic sewage in large cities
(a) has a high BOD as it contains both aerobic and anaerobic bacteria.
(b) is processed by aerobic and then anaerobic bacteria in the secondary treatment in sewage Treatment Plants
(c) when treated in STPs does not really require the aeration step as the sewage contains adequate oxygen.
(d) has very high amounts of suspended solids and dissolved salts.
30. During sewage treatment, biogases are produced which include:
(a) methane, oxygen, hydrogen sulphide
(b) hydrogen sulphide, methane, sulphur dioxide
(c) hydrogen sulphide, nitrogen, methane
(d) methane, hydrogen sulphide, carbon dioxide
31. A good producer of citric acid is:
(a) Pseudomonas
(b) Clostridium
(c) Saccharomyces
(d) Aspergillus
32. Microbe used for biocontrol of pest butterfly caterpillars is
(a) Trichoderma sp.
(b) Saccharomyces cerevisiae
(c) Bacillus thuringiensis
(d) Streptococcus sp.
33. Which metabolic process is performed by bectaria in bio gas plant ?
(a) Aerobic Respiration
(b) Cellular Respiration
(c) Anerobic Respiration
(d) Internal Respiration
34. Which of the following in sewage treatment removes suspended solids?
(a) Tertiary treatment
(b) Secondary treatment
(c) Primary treatment
(d) Sludge treatment
35. infarction is normally immediately given:
(a) Cyclosporin-A
(b) Statins
(c) Penicillin
(d) Streptokinase
36.Bio fertilizer means……
(a) Crop which shows rapid growth
(b) Cow dung and agricultural west
(c) prepared by Anabaena and Nostoc
(d) None of them
37. The guts of cow and buffalo possess
(a) Fucus sp
(d) Chlorella sp
(c) Methanogens
(d) Cyanobacteria
38. The free-living fungus Trichoderma can be used for
(a) killing insects
(b) producing antibiotics
(c) biological control of plant diseases
(d) controlling butterfly caterpillars
39. What gases are produced in anaerobic sludge digesters?
(a) Methane and CO2 only
(b) Methane, Hydrogen sulphide and CO2
(c) Methane, Hydrogen sulphide and O2
(d) Hydrogen sulphide and CO2
40. Which fungus is useful to prepare bread ?
(a) Rhizopus nigricans
(b) Saecharhomyces Cerrevisiae
(c) Clostridium Butirycum
(d) Asper Gillus Niger
41. Consider the following four statements (A D) and select the option which includes all the correct ones only.
(A) Single cell Spirulina can produce large quantities of food rich in protein, minerals, vitamins, etc.
(B) Body weightwise the microorganism Methylophilus methylotrophus may be able to produce several times more proteins than the cows per day.
(C) Common button mushrooms are a very rich source of vitamin C.
(D) A rice variety has been developed which is very rich in calcium.
(a) Statement (B), (C) and (D)
(b) Statements (C) and (D)
(c) Statements (A), (C) and (D)
(d) Statement (A) and (B)
42. Which one of the following is an example of carrying out biological control of pests/diseases using microbes?
(a) Trichoderma sp. against certain plant pathogens.
(b) Nucleopolyhedrovirus against white rust in Brassica.
(c) Btcotton to increase cotton yield.
(d) Lady bird beetle against aphids in mustard.
43.Which bacteria is useful for purification in sewage treatment ?
(a) Hetrotrops
(b) Symbiont
(c) Free living
(d) Parasist
44. A nitrogenfixing microbe associated with Azolla in rice fields is
(a) Frankia
(b) Tolypothrix
(c) Spirulina
(d) Anabaena
45. Which of the following microorganisms is used for production of citric acid in industries?
(a) Lactobacillus bulgaris
(b) Aspergillus niger
(c) Rhizopus nigricans
(d) Penicillium citrinum
46. By which process floating debris and grit are removed in STPs respectively ?
(a) Filteration and Sedimentation
(b) Filteration and Distilation
(c) Sedimentation and Filteration
(d) Only Filteration
47. Read the following four statements (AD).
(A) Colostrum is recommended for the new born because it is rich in antigens.
(B) Chikungunya is caused by a Gram negative bacterium.
(C) Tissue culture has proved useful in obtaining virusfree plants.
(D) Beer is manufactured by distillation of fermented grape juice
How many of the above statements are wrong?
(a) Four
(b) Two
(c) One
(d) Three
48. Formation of flocks means….
(a) Assoicated of virus with the bacteria remains in water
(b) Bactaria which associated with the mychoriza of the fungus of water
(c) Bactaria which associated with the mychorriza of the fungus of soil
(d) Bactaria which associated with the solid waste of the water
49. What would happen if oxygen availability to activated sludge flocs is reduced?
(a) It will slow down the rate of degradation of organic matter.
(b) Protozoa would grow in large numbers.
(c) The centre of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs.
(d) Flocs would increase in size as anaerobic bacteria would grow around flocs.
50. Which one of the following statements is correct?
(a) Legumes fix nitrogen only through
specialized bacteria that live in their leaves.
(b) Legumes fix nitrogen only through the specialized bacteria that live in their roots.
(c) Legumes fix nitrogen independently of the specialized bacteria that live in their roots.
(d) Legumes are incapable of fixing nitrogen
51. Which of the following is mainly produced by the activity of anaerobic bacteria on sewage?
(a) Mustard gas
(b) Marsh gas
(c) Laughing gas
(d) Propane
52. Continuous addition of sugars in ‘fed batch’ fermentation is done to
(a) purify enzymes
(b) degrade sewage
(c) produce methane
(d) obtain antibiotics
53. Select the mismatch :
(a) Rhodospirillum – Mycorrhiza
(b) Anabaena – Nitrogen fixer
(c) Rhizobium – Alfalfa
(d) Frankia – Alnus
54. Which of the following in sewage treatment removes suspended solids ?
(a) Secondary treatment
(b) Primary treatment
(c) Sludge treatment
(d) Tertiary treatment
55. Which of the following is correctly matched for the product produced by them ?
(a) Methanobacterium : Lactic acid
(b) Penicillium notatum : Acetic acid
(c) Sacchromyces cerevisiae : Ethanol
(d) Acetobacter aceti : Antibiotics
56. Conversion of milk to curd improves its nutritional value by increasing the amount of
(a) Vitamin D
(b) Vitamin A
(c) Vitamin E
(d) Vitamin B12
57. Which of the following is a commercial blood cholesterol lowering agent?
(a) Cyclosporin A
(b) Statin
(c) Streptokinase
(d) Lipases
58. Select the correct group of biocontrol agents.
(a) Bacillus thuringiensis, Tobacco mosaic virus, Aphids
(b) Trichoderma, Baculovirus, Bacillus thuringiensis
(c) Oscillatoria, Rhizobium, Trichoderma
(d) Nostoc, Azospirillium, Nucleopolyhedrovirus
59.Match the following organisms with the products they produce
(a) Lactobacillus (i) Cheese
(b) Saccharomyces (ii) Curd cerevisiae
(c) Aspergillus niger (iii)Citric Acid
(d) Acetobacter aceti (iv) Bread
(v) Acetic Acid
Select the correct option.
(a) (b) (c) (d)
(1) (ii) (iv) (v) (iii)
(2) (ii) (iv) (iii) (v)
(3) (iii) (iv) (v) (i)
(4) (ii) (i) (iii) (v)
60. Which of the following can be used as a biocontrol agent in the treatment of plant disease?
(a) Trichoderma
(b) Chlorella
(c) Anabaena
(d) Lactobacillus
61. Which of the following is put into Anaerobic sludge digester for further sewage treatment?
(a) Effluents of primary treatment
(b) Activated sludge
(c) Primary sludge
(d) Floating debris
62. Match the following columns and select the correct option.
Column-I Column-II
(a) Clostridium (i) Cyclosporin-A butylicum
(b) Trichoderma (ii) Butyric Acid polysporum
(c) Monascus (iii)Citric Acid purpureus
(d) Aspergillus niger (iv) Blood cholesterol lowering agent
(a) (b) (c) (d)
(1) (i) (ii) (iv) (iii)
(2) (iv) (iii) (ii) (i)
(3) (iii) (iv) (ii) (i)
(4) (ii) (i) (iv) (iii)
63. DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear as
(1) Bright blue bands
(2) Yellow bands
(3) Bright orange bands
(4) Dark red bands
64. Mutations in plant cells can be induced by:
(a) Zeatin
(b) Kinetin
(c) Infrared rays
(d) Gamma rays
65. Which of the following is not an objective of Biofortification in crops?
(a) Improve micronutrient and mineral content
(b) Improve protein content
(c) Improve resistance to diseases
(d) Improve vitamin content
66. Match List-I with List-II
List I List II
(a) Aspergillus niger (i) Acetic Acid
(b) Acetobacter aceti (ii) Lactic Acid
(c) Clostridium butylicum (iii) Citric Acid
(d) Lactobacillus (iv) Butyric Acid
Choose the correct answer from the options given below
(a) (b) (c) (d)
(1) (iv) (ii) (i) (iii)
(2) (iii) (i) (iv) (ii)
(3) (i) (ii) (iii) (iv)
(4) (ii) (iii) (i) (iv)
Solutions :
1.Solution: (c) ‘Each antibiotic is effective only against one particular kind of germ’ is not correct.
2.Solution: (b) Control of cancer is likely to be achieved in the coming two decades.
3. Solution: (a) Gobar gas contains mainly CH4 + CO2.
4.Solution: (a) Azotobacter is a free living nitrogen fixing bacterium, Rhizobium is symbiotic and found in the root nodules of leguminous plants, Anabaena occurs in assoction with Azolla. VAM is vesicular arbuscular mycorrhiza.
5. Solution: (a) Farmers have reported over 50% higher yields of rice by using the biofertilizer Azollapinnata.
6.Solution: (a) Azolla is a freshwater fern harbouring a bluegreen alga – Anabaena in its leaf cavities. The alga fixes atmospheric nitrogen and releases nitrogenous compounds in leaf cavities. This symbiotic system is the main source of algal biofertilizer in rice fields.
7.Solution: (a) Azolla and blue green algae- Anabaena form biofertilizer in rice fields.
8.Solution: (d) Escherichia coli is a bacterium found in human colon. On this bacterium scientists have made extensive genetic experiments to
make some vital chemicals like insulin. Another bacterium is Agrobacterium tumefaciens which causes crown gall in plants is extensively used for genetic experiments.
9.Solution: (c) Probiotics are defined as live microorganisms, including Lactobacillus species, Bifidobacterium species and yeasts, that may beneficially affect the host upon ingestion by improving the balance of the intestinal microflora. The dietary use of live microorganisms has a long history.
10.Solution: (c) Coliforms are a broad class of bacteria found in our environment, including the feces of man and other warm-blooded animals. The presence of coliform bacteria in drinking water may indicate a possible presence of harmful, diseasecausing organisms.
11.Solution: (d) Trichoderma harzianum has proved a useful microorganism for biological control of soil borne plant pathogens. Trichoderma
harzianum is a fungus that is also used as a fungicide. It is used for foliar application, seed treatment and soil treatment for suppression of various disease causing fungal pathogens. Commercial biotechnological products such as 3 Tac have been useful for treatment of Botrytis,
Fusarium, Penicillium sp. It is also used for manufacturing enzymes.
12.Solution: (a) Human insulin is being commercially produced from a transgenic species of Escherichia coli. E. coli is a bacterium that
is commonly found in the lower intestine of warm blooded animals. The bacteria can also be grown easily and its genetics are comparatively simple and easily manipulated, making it one of the best studied prokaryotic model organisms, and an important species in biotechnology.
13.Solution: (d) Cry I endotoxine obtained from Bacillus thuringiensis are effective against bollworms. A bollworm is a common term
for any larva of a moth that attacks the fruiting bodies of certain crops, especially cotton.
14.Solution: (d) A common biocontrol agent for control of plant diseases is Trichoderma. Trichoderma is a tree living fungus that exert biocontrol over several plant pathogens for the control of plant diseases. It is the natural method of pest and pathogen control.
15.Solution: (b) The common nitrogen fixer in paddy field is Azospirillum. It is an anaerobic bacteria that forms loose association with roots of
paddy crops.
16.Solution: (d) Organic farming involves use of organic wastes and other biological material along with beneficial microbes to release
nutrients to crop to increase the soil fertility in an ecofriendly, and pollution tree environment. Glomus, earthworm and Oscillatoria can be used in organic farming while snail cannot.
17.Solution: (c) Rhizobium is a nitrogen fixing bacteria, which acts as a biofertilizer in soil to produce soyabean crops.
18.Solution: (a) Glomus aggregatum is a mycorrhizal fungus used as a soil inoculant in agriculture and horticulture. Its purpose is to increase the surface area of roots for nutrient absorption like phosphorus.
19.Solution: (b) Trichoderma is a species of filamentous fungi. Cyclosporin A is immunosuppressive drug obtained from Trichoderma and used
in organ transplantation.
20.Solution: (c) Clostridium butylicum industrially produces butyric acid.
21.Solution: (d) Monascuspurpureus is a yeast used in the production of statins which are used in lowering blood cholestrol.
22.Solution: (b) Streptokinase is immediately given to dissolve the thrombus carring myocardial infarction
23.Solution: (c) Glomus is endomycorrhiza that helps in absorption of nutrition specially phosphorus from soil.
24.Solution: (c) Saccharomyces cervisiae is a yeast used in making bread (Baker‘s yeast) and commercial production of ethanol.
25.Solution: (b) Anabaena azollae resides in the leaf cavities of the fern Anabaena. It fixes nitrogen. A part of the fixed nitrogen is excreted in the cavities and becomes available to the fern. The decaying fern plants release the same for utilization of the rice plants.
26.Solution: (a)
27.Solution: (c)
28.Solution: (b) In gobar gas the maximum amount of methane which is produced by methanogenic bacteria. Gobar gas is a gas mixture which is generated when organic compounds are fermented in the absence of air (anaerobic fermentation). Biogas contains 50 – 70% methane, 30 – 40%
carbon dioxide, and traces of hydrogen, hydrogen sulphide and nitrogen. Methane is a combustible gas, which means it can be burned. It can be used as a fuel for cooking and lighting.
29.Solution: (b) Sewage treatment is the process of removing contaminants from wastewater and household sewage, both runoff (effluents) and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants. Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment. It is processed by aerobic and then anaerobic bacteria in the secondary treatment in Sewage Treatment Plants (STPs).
30.Solution: (d) The major component of biogas is methane (about 50-68%) which is highly inflammable. The other gases are carbon
dioxide (25 – 35%), hydrogen (1 – 5%), nitrogen (2 – 7%), Oxygen (0 – 0.1%) and rarely hydrogen sulfide. Biogas is a ―mixture of gases‖ produced from degradable organic matter by the activity of various anaerobic bacteria that offers a low cost alternative for energy requirements.
31.Solution: (d) A good source of citric acid is Aspergillus niger (a fungus). Apart from citric acid, oxalic acid, gallic acid, gluconic acid are
extracted from fungus.
32. Solution: (c) Microbial biocontrol agent that can be introduced in order to control butterfly caterpillars is the bacteria Bacillus thuringiensis (Bt). They sprayed onto vulnerable plants, where they eaten by the insect larvae. In the gut of the larvae, the toxin is released and the larvae get killed. The bacterial disease will kill the caterpillars, but leave other insects unharmed
33.(c) Anaerobic digestion, or the decomposition of organic matter by bacteria in the absence of oxygen, occurs naturally in liquid manure systems. Anaerobic bacteria transform manure and other organic material into biogas and a liquefied effluent during the three stages of biogas production
34.(c) In sewage treatment, suspended solids are removed during primary treatment. It is also known as physical treatment. It consists of shredding, churning, screening and sedimentation. Sequential filtration removes floating and large suspended solids.
35.(d) Streptokinase is a thrombolytic medication and enzyme. As a medication it is used to break down clots in some cases of myocardial infarction (heart attack), pulmonary embolism, and arterial thromboembolism. The type of heart attack it is used in is an ST elevation myocardial infarction.
36.(c) prepared by Anabaena and Nostoc
37.(c) Methanogens like Methanobacterium are found in the rumen (a part of the stomach) of cattle. A lot of cellulosic material is also available in the rumen. In rumen, these bacteria help in the breakdown of cellulose and play an important role in nutrition of cattle.
38.(d) Trichoderma as biological control agents have been widely used against many plant pathogens, such as viruses, bacteria, fungi, nematodes, and higher parasitic plants
39.(b) Methane, hydrogen sulphide and CO2 are gases that are produced in anaerobic sludge digesters. These gases are produced during bio-gas production by the activity of bacteria called methanogens.
40.(b)Saccharomyces cerevisiae, also know as baker’s yeast, is an important ingredient in bread, a food that has been considered a staple of human life for thousands of years.
41.(d) Both A and B
42.(d) A biological control being developed for use in the treatment of plant disease is the fungus Trichoderma. Trichoderma species are free living fungi that are very common in the root ecosystems. They are effective biocontrol agents of several plant pathogens.
43.(a) Hetrotrops
44.(d) Azolla plays a very important role in rice production. Azolla and its nitrogen-fixing partner, Anabaena, have been used as green manure to fertilize rice paddies and increase production. With the help of Azolla, rice can be grown year after year, several crops a year, with little or no decline in productivity; hence no rotation of crops is necessary.
45.(b) Citric acid is the most important organic acid produced in tonnage and is extensively used in food and pharmaceutical industries. It is produced mainly by submerged fermentation using Aspergillus niger or Candida sp. from different sources of carbohydrates, such as molasses and starch based media.
46.(a) Filteration and Sedimentation
47.(d)Colostrum is the first breast milk of mother which contains antibodies Chikungunya is a viral disease transmitted to humans by infected mosquitoes. It is caused by the chikungunya virus Beer is manufactured by fermentation of barley malt by yeast species.
48.(b) Bactaria which associated with the mychoriza of the fungus of water
49.(c) The center of flocs will become anoxic, which would cause death of bacteria and eventually breakage of flocs.
50.(b) Legumes fix nitrogen only through the specialized bacteria that live in their roots.
51.(b) Marsh gas
52.(a) Continuous addition of sugars in ‘fed batch’ fermentation is done to purify enzymes.
53 (a)Rhodospirillum is a facultative anaerobe and a free living nitrogen fixer. Mycorrhiza are symbiotic association of fungi and higher plant roots.
Anabaena is a genus of filamentous cyanobacteria that exist as plankton. They are known for nitrogen-fixing abilities, and they form symbiotic relationships with certain plants. an effective way of improving nitrogen fixation in alfalfa is to select for a favourable combination of specific Rhizobium strains and alfalfa cultivars. Alnus is the most widely distributed actinorrhizal plant genus that associates with the Frankia alni species complex.
54. (b) There are three main stages of the wastewater treatment process, aptly known as primary, secondary and tertiary water treatment. Secondary treatment is a treatment process for wastewater to achieve a certain degree of effluent quality by using a sewage treatment plant with physical phase separation to remove settleable solids and a biological process to remove dissolved and suspended organic compounds.
Primary treatment removes about 60 percent of total suspended solids and about 35 percent of BOD. The hydrolyzed sludge is passed through a flash tank, where a sudden drop in pressure causes cells to burst, and then to anaerobic digestion, where bacteria convert dissolved organic matter to biogas (which can be used to fuel the treatment process). Tertiary treatment is the final cleaning process that improves wastewater quality before it is reused, recycled or discharged to the environment. The treatment removes remaining inorganic compounds, and substances, such as the nitrogen and phosphorus.
55. (c)S. cerevisiae is the most employed yeast for ethanol production at industrial level though ethanol is produced by an array of other yeasts, bacteria, and fungi.
56 (d) Lactobacillus species is reason to conversion of milk into curd. This bacteria helps in increasing nutrition value of B12
57 (b) Statins are a class of drugs often prescribed by doctors to help lower cholesterol levels in the blood. Statins, also known as HMG-CoA reductase inhibitors, are a class of lipid-lowering medications that reduce illness and mortality in those who are at high risk of cardiovascular disease.
58 (b) Biocontrol refers to the use of biological methods for controlling plant diseases and pests. Chemicals, insecticides and pesticides are extremely harmful to human beings and also these pollute our environment. Fungs Trichoderma, Baculoviruses (NPV) and Bacillus thuringiensis are used as biocontrol agents. Trichoderma are the most widely used fungal biocontrol agents against fungal diseases of pulses, grapes, cotton, onion, carrot, peas, plums, maize, apple, etc. Baculoviruses are insect pathogenic viruses that are used for pest insect control and as tools to produce recombinant proteins. Bacillus thuringiensis (B.t.) is a natural spore-forming bacterium that occurs in soils everywhere. When larvae ingest B.t., it destroys the lining in their gut, and they stop feeding and die within days.
59(1) Lactobacillus is a type of bacteria . The Lactobacillus bacteria grow on lactose and produce lactic acid as a byproduct of fermentation.
Saccharomyces is a genus of fungi that includes many species of yeasts. bakers use a specific type of yeast, known as Saccharomyces cerevisiae, or “sugar-eating fungus”. Although small, this species of yeast is very strong and capable of fermentation, which is the process that causes bread dough to rise.
60(a) Trichoderma spp. are the most widely used fungal biocontrol agents against fungal diseases of pulses, grapes, cotton, onion, carrot, peas, plums, maize, apple, etc.
61(b) The activated sludge process is a type of wastewater treatment process for treating sewage or industrial wastewaters using aeration and a biological floc composed of bacteria and protozoa.
62 (4) (a) Clostridium butylicum — Butyric acid
(b) Trichoderma polysporum — Cyclosporin-A
(c) Monascus purpureus — Blood cholesterol lowering agent
(d) Aspergillus niger — Citric acid
63(c) After the bands are stained, they are viewed in UV light. The bands appear bright orange in colour. Ethidium bromide is the intercalating agent that stacks in between the nitrogenous bases.
64 (d) Gamma rays
65 (c) Biofortification improves vitamin content, protein content and micronutrient and mineral content. It does not create resistance in plants against diseases.
66 (2) (iii) (i) (iv) (ii)
