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Quiz 5
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Q.1
An example of endomycorrhiza is ... [ CBSE Mains 2010]
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a) Glomus
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b) Agaricus
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c) Nostoc
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d) Rhizobium
Explanation
Endomycorrhizas include arbuscular (AMs), ericoid, and orchid mycorrhizas. Arbuscular mycorrhizal fungi are soil fungi belonging to the phylum Glomeromycota. Glomus belongs to Glomeromycota Answer:(a)
Q.2
The earliest pesticide was ... [ MPPMT 19990]
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a) DDT
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b) Margosa
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c) Pyrethrum
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d) Nicotine
Explanation
A number of insects are repelled by azadirachtin from Margosa due to antifeedant property. It was perhaps the first natural insecticide usd by humans. Answer:(b)
Q.3
The process of increasing fertility of soil by Earthworms is ... [ AMU 2011]
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a) Worm casting
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b) Vermicomposting
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c) Compost bedding
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d) None of the above
Explanation
Vermicompost is the product of the decomposition process using various species of worms, usually red wigglers, white worms, and other earthworms, to create a mixture of decomposing vegetable or food waste, bedding materials, and vermicast. Answer:(b)
Q.4
Pyrethrin is got from ... [ BHU 2002]
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a) Tagetes erecta
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b) Azadirachta indica
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c) Chrysanthemum cinerariifolium
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d) Urtica dioica
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:(c)
Q.5
Antibiotic cephalosporin is got from ...[ JIPMER 1999]
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a) Fungus
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b) Bacterium
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c) Alga
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d) Mycoplasma
Explanation
Cephalosporin is obtained from marine fungus Cephalosporium acremonium. Answer:(a)
Q.6
Most famous nitrogen fixing bacterium/biofertilizers is ... [ JIPMER 2000]
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a) Nitrobacter
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b) Nitrosomonas
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c) Nitrococcus
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d) Rhizobium
Explanation
Rhizobium is the most famous nitrogen-fixing bacteria or biofertilizer. It is an endosymbiotic nitrogen-fixing bacteria which consists of roots of legumes and it is colonized within the root nodules in plant cells. Answer:(d)
Q.7
Which of the following is mainly produced by the activity of anaerobic bacteria on sewage ...[ CBSE 2011]
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a) Propane
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b) Laughing gas
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c) Marsh gas
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d) Mustard gas
Explanation
Activity of anaerobic bacteria on sewage in anaerobic sludge digester produces mixture of carbon dioxide, hydrogen sulphide and carbon dioxide. This is known as marsh gas or biogas. Answer:(c)
Q.8
Pasteurisation is
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a) Heating of liquid at 65°C
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b) Heating of liquid between 65° - 80°C followed by rapid cooling
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c) Heating of solids at 65°C
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d) None of these
Explanation
Pasteurisation is the process of heating up milk and other liquids to a high temperature for a short time and then cooling it down again quickly. The standard temperature used for the process is 71.7°C and the length of time it's kept at that temperature for has to be at least 15 seconds and no longer than 25 seconds Answer:(b)
Q.9
Which is a microbial insecticide? [ AIIMS 1997]
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a) Bacillus thuringiensis
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b) B. subtilis
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c) B. polymixa
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d) B. brevis
Explanation
Bacillus thuringiensis is a Gram-positive, soil-dwelling bacterium, the most commonly used biological pesticide worldwide B. subtilis is used in synthesis of protease. Polymyxin B is an antibiotic derived from the bacterium Bacillus polymyxa, primarily used for the treatment of resistant Gram-negative infections. The soil bacterium Bacillus brevis produces a mixture of short polypeptides, gramicidins A, B, and C, which are collectively called gramicidin D (or just gramicidin), an important antibiotic that effectively kills gram-positive bacteria. Answer:(a)
Q.10
Distribution of clean and quality milk through the world has been made possible through work of ... [ AIIMS 1990]
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a) Leeuwenhoek
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b) Koch
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c) Pasteur
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d) Blackman
Explanation
Louis Pasteur ForMemRS was a French chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation, and pasteurization. Pasteurisation is process intended to destroy or deactivate organisms and enzymes that contribute to spoilage or risk of disease, including vegetative bacteria, but not bacterial spores resulting in clean and good quality milk. Answer:(c)
Q.11
Cowdung is appropriately used as ... [ DPMT 2001]
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a) Fuel
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b) Medicine
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c) Manure
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d) Building material
Explanation
Cow dung has capability to improve the soil structure (aggregation) so that the soil holds more nutrients and water, and therefore becomes more fertile. Thus, it is used as manure. Answer:(c)
Q.12
Germinating Barley seeds are used in preparation of ... [ EAMCET 1987]
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a) Beer
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b) Lactic acid
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c) Wine
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d) Cheese
Explanation
Beer’s nutrient medium is Barley (Hordeum vulgare) grain which have been semi germinated and crushed to form malt. Before inoculation with yeast, the infusion of malt is treated with hops (Humulus lupulus) to provide flavor, colour and stability. Answer:(a)
Q.13
Which of the following can be controlled by using biopesticide? ...[ MPPMT 2009]
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a) Insects
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b) Diseases
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c) Weeds
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d) All the above
Explanation
Biopesticides are currently used to manage invertebrate pests, plant pathogens, and weeds. The microorganisms used include bacteria, yeasts, fungi, and viruses. Advantages of biopesticide are as follows: Control pests, pathogens, diseases and weeds. Answer:(d)
Q.14
Which proves to be effective biological control for nematodal pathogens of plants? ...[ CBSE 2008]
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a) Pseudomonas cepacia
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b) Pisolithus tinctorius
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c) Gliocladium virens
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d) Paecilomyces lilacinus
Explanation
The egg pathogenic fungus Paecilomyces lilacinus (strain 251) is a biocontrol fungus with a potential range of activity to control the worldwide most important plant parasitic nematodes. This biological nematicide may be an useful tool in an integrated approach to control mainly sedentary nematodes. Answer:(d)
Q.15
Modern detergents contain enzyme preparations of ...[ CBSE 2008]
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a) Thermoacidophiles
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b) Alkaliphiles
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c) Thermophiles
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d) Acidophiles
Explanation
Modern detergents contains alkaline proteases also known as alkaliphiles which are helpful in removing protein based stains. Answer:(b)
Q.16
Assertion: Leguminous plants are best preferred for rotation of crops Reason: They have root nodules which possess nitrogen fixing bacterium Clostridium ..[ AIIMS 2000]
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a) Both are true with reason being correct explanation
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b) Both are true but reason is not correct explanation
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c) Assertion is true but reason is wrong
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d) Both are wrong
Explanation
Leguminous plants are in symbiotic relationship with Rhizobium. These nitrogen fixing bacteria converts atmospheric content into ammonia. This result in increase in nitrogen content in soil. Thus, leguminous plants are best preferred for rotation of crops. Answer:(c)
Q.17
VAM represents .... [ HPPMT 1994]
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a) Saprophytic fungi
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b) Symbiotic fungi
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c) Saprophytic bacteria
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d) Symbiotic bacteria
Explanation
Vesicular-arbuscular mycorrhiza (VAM) is formed by the symbiotic association between certain phycomycetous fungi and angiosperm roots. The fungus colonizes the root cortex forming a mycelial network and characteristic vesicles (bladder-like structures) and arbuscules (branched finger-like hyphae). Answer:(b)
Q.18
Leghaemoglobin occurs in ... [ Bih. PMT 1996]
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a) Coralloid root
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b) BGA
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c) Around bacteroides
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d) Mycorrhiza
Explanation
Leghemoglobin (also leghaemoglobin or legoglobin) is an oxygen-carrying phytoglobin found in the nitrogen-fixing root nodules of leguminous plants. It is produced by these plants in response to the roots being colonized by nitrogen-fixing bacteria, termed rhizobia, as part of the symbiotic interaction between plant and bacterium. Therefore, it occurs around bacteriodes. Answer:(c)
Q.19
Thurioside is proteinaceous toxin obtained from ... [ AFMC 1999]
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a) Bacterial origin
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b) Biofertilizers
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c) Green manure
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d) Farmyard manure
Explanation
Thurioside is toxin obtained from Bacillus thuringiensis is toxic to several insects. Answer:(a)
Q.20
Sewage treatment process in which part of decomposer bacteria is recycled into starting of the process is called ...[ DPMT 2009]
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a) Cyclic treatment
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b) Primary treatment
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c) Tertiary treatment
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d) Activated sludge treatment
Explanation
A sewage treatment process in which a part of decomposer bacteria present in the wastes is recycled into the starting of the process is called activated sludge treatment . Answer:(d)
Q.21
Which is a wrong matching .. [ CBSE Main 2011]
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a) Yeast -statins
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b) Acetobacter aceti - Acetic acid
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c) Aspergillus niger - Citric acid
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d) Clostridium butylicum - Lactic acid
Explanation
Clostridium butylicum produces butyric acid. Lactic acid is produced by Streptococcus lactis, Lactobacillus bulgaricus. Answer:(d)
Q.22
Yeast is used in preparation of ... [ MPPMT 2000]
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a) Ethyl alcohol
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b) Acetic acid
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c) Curd
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d) Cheese
Explanation
Yeast is used in preparation of alcohol. Answer:(a)
Q.23
During lactic acid fermentation ... [ KCET 2010]
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a) O2 is used, CO2 is liberated
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b) Neither O2 is used nor CO2 liberated
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c) O2 is not used, CO2 is liberated
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d) O2 is used, CO2 is not liberated
Explanation
Lactic acid fermentation is a metabolic process by which glucose or other six-carbon sugars (also, disaccharides of six-carbon sugars, e.g. sucrose or lactose) are converted into cellular energy and the metabolite lactate, which is lactic acid in solution. It is an anaerobic fermentation reaction that occurs in some bacteria and animal cells, such as muscle cells. It is anaerobic respiration and thus O2 is not used. The end- product is lactate and ATP, thus CO2 is not liberated. Answer:(b)
Q.24
Mycorrhiza acts as ...[ BHU 2002]
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a) Mechanical tissue
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b) Root hair in adverse conditions
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c) Modified root
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d) Organ for vegetative propagation
Explanation
The mechanisms by which mycorrhizae increase absorption include some that are physical and some that are chemical. Physically, most mycorrhizal mycelia are much smaller in diameter than the smallest root or root hair, and thus can explore soil material that roots and root hairs cannot reach, and provide a larger surface area for absorption. Under adverse conditions, mycorrhiza act as root hair. Answer:(b)
Q.25
Which among these are produced without distillation of fermented broth ... (a) Whisky (b) Wine (c) Beer (d) Rum (e) Wine
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a) b and c alone
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b) a and b alone
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c) a, b and e
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d) c and d alone
Explanation
Wine and beer are produced without distillation, where as Whisky Rum are produced by distillation of fermented broth Answer:(a)
Q.26
Which ones are involved in preparation of alcohol ..[ MPPMT 2001]
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a) Yeasts
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b) Slime Mould
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c) Bacteria
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d) Water Mould
Explanation
Yeast is used in preparation of alcohol. Answer:(a)
Q.27
Which of the following weed should be eradicated quickly? ... [ Pb PMT 2007]
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a) Parthenium
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b) Opuntia
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c) Vallisneria
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d) Eichhornia
Explanation
Parthenium hysterophorus is a noxious weed in America, Asia, Africa and Australia. This weed is considered to be a cause of allergic respiratory problems, contact dermatitis, mutagenicity in human and livestock and thus should be eradicated quickly. Answer:(a)
Q.28
Product of fermentation of glucose by Yeast is ... [ MPPMT 1999]
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a) (C6H10O5)n
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b) C2H5OH
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c) C6H12O6
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d) CH3OH
Explanation
Yeast produces enzyme zymase which converts glucose into ethanol. Molecular formula of ethanol is C2H5OH. Answer:(b)
Q.29
Mode of action of Novobiocin is ... [ CET Chd 2010]
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a) Induces abnormal protein synthesis
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b) Inhibits cell wall synthesis
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c) Interferes with protein synthesis
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d) Inhibits DNA polymerisation
Explanation
Novobiocin is an aminocoumarin antibiotic, produced by the actinomycete Streptomyces nivens, with antibacterial property. Novobiocin, as well as other aminocoumarin antibiotics, inhibits bacterial DNA synthesis by targeting at the bacteria DNA gyrase and the related enzyme DNA topoisomerase IV. This antibiotic was used to treat infections by gram-positive bacteria. Answer:(d)
Q.30
Streptomycin is prepared from ... [ AIIMS 2001]
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a) Streptomyces antibioticus
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b) Streptomyces nodosus
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c) Streptomyces griseus
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d) Streptomyces rimosus
Explanation
Streptomycin is prepared from Streptomyces griseus. Answer:(c)
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