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Q.1
Which one among the following components of vermicompost contains plant growth factors ...
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a) Humic acid
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b) Nitrogen
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c) Microbes
0%
d) Phosphorus
Explanation
Vermicomposting is composting of organic matter with the help of earthworms. Worm castings are rich of phosphorus, nitrogen, calcium and humic acid and other minerals. Humic acids chemically change the fixation properties of the soil, with benefits such as: Neutralizes both acid and alkaline soils; regulates the pH-value of soils. Improves and optimizes the uptake of nutrients and water by plants. Increases buffering properties of soil. Answer:(a)
Q.2
Which one is a symbiotic nitrogen fixing plant ... [ DPMT 2008]
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a) Azolla
0%
b) Marchantia
0%
c) Moss
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d) Pinus
Explanation
Azolla pinnata is a small aquatic fern inoculated to rice fields of south-east Asian countries. It contains symbiont Anabaena in its leaf cavities. Increase in yield is more than 50%. Answer:(a)
Q.3
Which is correct? ...[ CBSE 1994]
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a) Legumes fix nitrogen through bacteria in their leaves
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b) Legumes fix nitrogen through bacteria in their roots
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c) Legumes fix nitrogen independent of bacteria
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d) Legumes do not fix nitrogen
Explanation
Root of legumes is in mutual beneficial association with Rhizobium. This association helps legumes fix atmospheric nitrogen to ammonia. Answer:(b)
Q.4
Citric acid is got from ... [ MPPMT 1998]
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a) Aspergillus niger
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b) Rhizobium nigricans
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c) Penicillium citrinum
0%
d) Lactobacillus bulgaricus
Explanation
Apergillus niger, Mucor species and yeast(when medium is deficient in Fe and Mn) can ferment sugar to produce citric acid. Answer:(a)
Q.5
Fermentation of sugar to yield alcohol is carried out by ... [ MPPMT 1994]
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a) Microorganisms
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b) Zymase
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c) Raised temperature
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d) Decomposition of sugar
Explanation
Yeast produces three enzymes- amylase, maltase and zymase complex. Amylase converts small quantity of starch into maltose. Maltase converts maltose to glucose. Zymase complex acts on glucose to produce ethanol. Answer:(b)
Q.6
Bacillus thuringiensis is used as ...[ Odisha 2010]
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a) Fungicide
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b) Weedicide
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c) Insecticide
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d) Biopesticide
Explanation
microbial biocontrol agents that can be introduced in order to control butterfly caterpillars is the bacteria Bacillus thuringiensis (often written as Bt) Answer:(d)
Q.7
Broad spectrum antibiotics are the ones which attack ... [ AFMC 2001]
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a) Pathogens as well as hosts
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b) A wide range of pathogens
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c) Only a pathogen
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d) Only host
Explanation
Broad spectrum antibiotics are the antibiotics which can kill or destroy a number of pathogens that belongs to different groups with different structures and wall composition. Answer:(b)
Q.8
nzyme that changes glucose to ethyl alcohol is ...[ MPPMT 1998]
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a) Zymase
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b) Diastase
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c) Invertase
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d) Maltase
Explanation
Yeast produces three enzymes- amylase, maltase and zymase complex. Amylase converts small quantity of starch into maltose. Maltase converts maltose to glucose. Zymase complex acts on glucose to produce ethanol. Answer:(a)
Q.9
In gobar gas, the maximum amount is that of ...[ CBSE Mains 2012]
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a) Butane
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b) Propane
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c) Carbon dioxide
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d) Methane
Explanation
The main ingredient of biogas is methane (50-70%). Other components are carbon dioxide (25-35%), hydrogen(1-5%), nitrogen (2-7%) and hydrogen sulphide(traces). Answer:(d)
Q.10
Mycorrhiza represents ...[ CBSE 1994]
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a) Antagonism
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b) Symbiosis
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c) Parasitism
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d) Endemism
Explanation
Mycorrhiza is a mutually beneficial relationship between fungus and roots of higher plants. Mycorrhiza helps in absorption of water, minerals from organic matter and protection from soil borne pathogenic fungi. Answer:(b)
Q.11
Mycorrhiza is helpful in ...[ CPMT 2003]
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a) Synthesis of food
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b) Getting nutrients from soil
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c) Providing resistance against different regulators
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d) Increase the fertility of soil
Explanation
Mycorrhiza is a mutually beneficial relationship between fungus and roots of higher plants. Mycorrhiza helps in absorption of water, minerals from organic matter and protection from soil borne pathogenic fungi. Answer:(b)
Q.12
Which is linked to discovery of Bordeaux mixture as fungicide? ... [ CBSE 2008]
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a) Black rust of Wheat
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b) Loose smut of Wheat
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c) Bacterial leaf blight of Rice
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d) Downy mildew of Grapes
Explanation
Bordeaux mixture—a combination of copper sulfate, lime, and water—is an effective fungicide and bactericide that has been used for decades to control diseases of fruit and nut trees, vine fruits, and ornamental plants. The Bordeaux mixture fungicide (copper sulfate and lime), discovered accidentally in 1882, was used successfully against vine downy mildew; this compound is still employed to combat it and potato blight Answer:(d)
Q.13
Which is fungicide ...[ CBSE 2011]
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a) DDT
0%
b) DCMU
0%
c) Bordeaux mixture
0%
d) 2.4-D
Explanation
Bordeaux mixture—a combination of copper sulfate, lime, and water—is an effective fungicide and bactericide that has been used for decades to control diseases of fruit and nut trees, vine fruits, and ornamental plants Answer:(c)
Q.14
Yield of Paddy field can be increased by application of ... [ CBSE 1999]
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a) Iron bacteria
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b) Nostoc/ Anabaena
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c) Archaebacteria
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d) Symbiotic bacteria
Explanation
Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen, e.g. Anabaena, Nostoc, Oscillatoria, etc. In paddy fields, cyanobacteria serve as an important biofertiliser. Blue green algae also add organic matter to the soil and increase its fertility Answer:(b)
Q.15
They help in increasing soil fertility ... [ Wardha 2011]
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a) Salvinia and marsilea
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b) Nostoc and legumes
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c) Bacillus and Penicillium
0%
d) Pseudomonas and cereals
Explanation
Nostoc and legumes are biofertilizers and increase soil fertility. Bacillus and Penicillium are used in synthesis of antibiotics. Answer:(b)
Q.16
The first antibiotic was discovered by ...[ KCET 2004]
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a) A. Fleming
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b) R. Koch
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c) W. Flemming
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d) Louis Pasteur
Explanation
Rene Dubois was first to produce an antibiotic named tyrothricin from Bacillus brevis. However, first antibiotic is henerally associated with the name of Alexander Fleming when he discovered penicillin form Penicillium notatum. Answer:(a)
Q.17
During fermentation by Yeast, alcohol is formed from ...[ Odisha 1997]
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a) Proteins
0%
b) Sugars
0%
c) Mucopolysaccharides
0%
d) Fats
Explanation
Yeast produces three enzymes- amylase, maltase and zymase complex. Amylase converts small quantity of starch into maltose. Maltase converts maltose to glucose. Zymase complex acts on glucose to produce ethanol. Answer:(b)
Q.18
Trichoderma harzianum is useful for ...[ DPMT 2010]
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a) Gene transfer in higher plants
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b) Biological control of soil borne pathogens/ biopesticide
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c) Bioremediation of Contaminated Soil.
0%
d) Reclamation of waste land
Explanation
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 Answer:(b)
Q.19
Which group is responsible for formation and flavour of yoghurt ... [ Pb PMT 2005]
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a) Bacillus Megaterium and Xanthomonas sp.
0%
b) Lactobacillus casei and Streptococcus thermophilus
0%
c) Bacillus subtilis and E.Coli
0%
d) Rhizobium meliloti and Azotobacter
Explanation
Try again
Q.20
Lactic acid bacteria converts milk into curd and improves its nutritional quality by enhancing vitamin ...[ AMU 2009]
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a) A
0%
b) B
0%
c) C
0%
d) D
Explanation
Micro-organisms such as Lactobacillus and others commonly called lactic acid bacteria (LAB) grow in milk and convert it to curd. During growth, the LAB produce acids that coagulate and partially digest the milk proteins. A small amount of curd added to the fresh milk as inoculum or starter contain millions of LAB, which at suitable temperatures multiply, thus converting milk to curd, which also improves its nutritional quality by increasing vitamin B12. In our stomach too, the LAB play very beneficial role in checking disease causing microbes. Answer:(b)
Q.21
Pyrethrin is extracted from ... [ RPMT 1989]
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a) Azadirachta indica
0%
b) Chrysanthemum cinerariifolium
0%
c) Poa indica
0%
d) Helianthus annuus
Explanation
The pyrethrins are a class of organic compounds normally derived from Chrysanthemum cinerariifolium that have potent insecticidal activity by targeting the nervous systems of insects. Answer:(b)
Q.22
If wheat field is inoculated with Rhizobium ... [ MPPMT 2009]
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a) Soil will become rich in calcium
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b) Soil will become nitrogen rich
0%
c) No effect on soil nitrogen
0%
d) Soil will become nitrogen rich
Explanation
Rhizobium in symbiotic relation with root of leguminous plants fix atmospheric nitrogen. Nitrogen is converted into ammonia. So, if wheat field is inoculated with Rhizobium will have no effect on soil nitrogen. It is possible only with legumes. Answer:(c)
Q.23
Streptomyces fradiae produces ...[ MPPMT 2001]
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a) Aureomycin
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b) Neomycin
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c) Erythromycin
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d) Terramycin
Explanation
Streptomyces fradiae produces Neomycin which used as antibacterial against gram negative bacilli and some gram positive bacteria. Aureomycin is produced by Streptomyces aureofaciens. Erythromycin is produced by S. erythreus. Terramycin is produced by S. rimosus. Answer:(b)
Q.24
One of the alternate sources of proteins for animal and human nutrition is ...[ HPPMT 2011]
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a) Single cell protein
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b) Pulse
0%
c) Mushrooms
0%
d) Non vegetarian meals
Explanation
Alternate source of proteins for animal and human nutrition is Single Cell Protein(SCP). It is protein rich microbial biomass and has all the essential amino acids. Algae, yeast and some fungus are raised as SCP. Answer:(a)
Q.25
Brown Plant Hopper is ...[ Kerala 2000[
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a) Nilaparvata lugens
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b) Calliphora erythrocephala/i>
0%
c) HHelicoverpa armigera
0%
d) Schistocerea gregaria
Explanation
The brown planthopper (BPH), Nilaparvata lugens (Hemiptera: Delphacidae) is a planthopper species that feeds on rice plants (Oryza sativa L.). Answer:(a)
Q.26
Fleming, Chain and Florey were awarded Nobel Prize in 1945 for the discovery of ...[ kerala 2011]
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a) HIV
0%
b) CT scan
0%
c) Penicillium
0%
d) Staphylococcus
Explanation
The Nobel Prize in Physiology or Medicine 1945 was awarded jointly to Sir Alexander Fleming, Ernst Boris Chain and Sir Howard Walter Florey "for the discovery of penicillin and its curative effect in various infectious diseases." Answer:(c)
Q.27
Which one is wrongly matched ...[ CBSE 2009]
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a) Detergent -lipase
0%
b) Fruit juice - pectinase
0%
c) Alcohol - nitrogen
0%
d) Textile - amylase
Explanation
Zymase enzyme produced by yeast converts glucose into alcohol and in this process carbon dioxide is also obtained as by-product. Answer:(c)
Q.28
Supply of oxygen to the biogas plant will have ...[ Wardha 2005]
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a) Positive effect
0%
b) Negative effect
0%
c) No effect
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d) None of these
Explanation
Biogas also known as marsh gas is produced by anaerobic bacteria. Anaerobic bacteria breakdown organic matter into monomers and then into organic acids. Organic acids are then converted into mthane, hydrogen sulphide and carbon dioxide by methanogens. Supply of oxygen will hinder process of anaerobic bacteria and thus have negative effect. Answer:(b)
Q.29
Penicillin inhibits bacterial multiplication because it ...[ CPMT 1998]
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a) Destroys chromatin
0%
b) Inhibits cell wall formation
0%
c) Checks DNA synthesis
0%
d) Check RNA synthesis
Explanation
Try again
Q.30
Fungus used for commercial production of SCP is ... [ Kerala 2009]
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a) Phytophthora infestans
0%
b) Fusarium graminearum
0%
c) Brassica napus
0%
d) Bacillus thuringiensis
Explanation
Single cell protein typically refers to source of mixed protein extracted from pure or mixed culture of algae, yeast, fungi or bacteria. The most common source of single cell protein are single celled yeast e.g. Candida utilis and filamentous fungus like Fusarium graminearum. Answer:(b)
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