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Quiz 6
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Q.1
Match the columns ..[ KCET 2001]
Column I
Column II
(a) Neomycin
(p)
Streptomyces fradiae
(b) Terramycin
(q)
Penicillium notatum
(c) Viridin
(r) Streptomyces rimosus
(d) Penicillin
(s)
Gliocladium virens
0%
a) (a) - (r); (b) - (p), (c) - (s); (d) - (q)
0%
b) (a) - (p); (b) - (r), (c) - (s); (d) - (q)
0%
c) (a) - (r); (b) - (r), (c) - (p); (d) - (q)
0%
d) (a) - (s); (b) - (p), (c) - (r); (d) - (r)
Explanation
Neomycin is prepared from Steptomyces fradiae. Terramycin is prepared from Streptomyces rimosus. Viridin is prepared from Gliocladium virens. Penicillin is prepared from Penicillium chrysogenum and Penicillium notatum. Answer:(b)
Q.2
In cheese microorganisms are required for ...[ CBSE 1994]
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a) Ripening
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b) Souring and ripening
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c) Souring of milk
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d) Development of resistance to spoilage
Explanation
Raw cheese is prepared by coagulating milk using acid or Lactic Acid Bacteria(LAB). This process is called souring. Ripening is carried out to provide cheese with a characteristics texture, flavor and taste. It is carried out with the help of specific microbes. Example: Penicillium camembertii and Penicillium roquefortii. Answer:(b)
Q.3
Biofertilizers include ...[ CBSE 2001]
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a) Cow dung manure and farmyard waste
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b) A quick growing crop ploughed back
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c) BGA/ Anabaena
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d) All the above
Explanation
Biofertilizers are the organism which bring about nutrient enrichment of the soil. BGA/Anabaena is free living nitrogen fixing cyanobacteria. Answer:(c)
Q.4
Which one of the following is free living nitrogen fixing bacterium // [ JKCMEE 2008]
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a) Pseudomonas
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b) Azotobacter
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c) Cyanobacteria
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d) Anabaena azollae
Explanation
Free living nitrogen fixing bacterium are Azotobacter, Clostridium, Rhodopseudomonas, Rhodospirillum, Chromatium. Answer:(b)
Q.5
Which organic compound is produced by fermentation and is used to partially replace fossil fuel ..[ Odisha 2011]
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a) Ethanol
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b) Methanol
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c) Propanol
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d) Butanol
Explanation
Sugar or sugar based product like molasses is fermented to produce ethanol. Ethanol also act as biofuel Answer:(a)
Q.6
Which is false about antibiotics? ...[ JIPMER 2000]
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a) Antibiotics are capable of curing any disease
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b) The term was coined by Waksman in 1942
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c) Some persons develop allergy to antibiotics
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d) Antibiotics are produced by micro-organisms
Explanation
Antibiotics is a substance produced by microorganism which in low concentration inhibits the growth and metabolic activity of pathogenic organisms without harming the host. The term was coined by Wakesman (1942). Antibiotics is used to cure bacterial disease, not all disease can be cured. Answer:(a)
Q.7
Bt toxin is got from a ... [ DPMT 2007]
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a) Eukaryote
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b) Prokaryote
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c) Virus
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d) All the above
Explanation
Bt toxin is obtained from B. thuringiensis, gram positive, soil-dwelling bacterium. Answer:(b)
Q.8
Green manure plants belong to ... [ CET Chd1997]
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a) Compositae
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b) Solanaceae
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c) Poaceae
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d) Leguminosae
Explanation
Green manure plants are young leguminous plants. Example sunn hemp, sweet clover, Egyptian clover. Answer:(d)
Q.9
Lactobacillus mediated change of milk to curd occurs due to .. ..[ DPMT2010]
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a) Coagulation and partial digestion of milk fats
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b) Coagulation and partial digestion of milk proteins
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c) Coagulation of milk proteins and complete digestion of proteins
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d) Coagulation of milk fats and complete digestion of proteins
Explanation
Lactobacillus produces lactase which converts milk sugar lactose into lactic acid. It also partially digest milk protein casein. Lactic acid produced coagulates protein to form curd. Answer:(b)
Q.10
Which of the following statements is not true for stirred tank fermentation? [ Odisha 2005]
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a) Easy in process sampling
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b) Control dissolved oxygen
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c) Buffer needed to control
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d) Easy in process sampling
Explanation
Stirred tank fermenter bioreactors (STBRs) are the reactors most widely employed for culturing of biological agents such as cells, enzymes, or antibodies. They are contractors where the well-mixed among phases is obtained mainly by internal mechanical agitation. It does not control dissolved oxygen. Answer:(b)
Q.11
Red pigment (leghaemoglobin) having affinity for oxygen is present in the roots of ... [ CBSE 2001]
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a) Carrot
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b) Soybean
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c) Mustard
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d) Radish
Explanation
Rhizobium is a symbiotic nitrogen fixing bacteria. It has mutually beneficial relation with leguminous plants. Root nodules has leghaemoglobin. Soybean belongs to leguminous plants. Answer:(b)
Q.12
Which of the following is not used in organic farming ...[ CBSE 2010]
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a) Earthworm
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b) Oscillatoria
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c) Snail
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d) Glomus
Explanation
Organic farming is an agricultural system that uses fertilizers of organic origin such as compost manure, green manure, and bone meal and places emphasis on techniques such as crop rotation and companion planting. Glomus being a mycorrhizal component, earthworm being a vermicompost and Oscillatoria being a nitrogen fixing blue green algae can be used in organic farming. Snail cannot be a component of organic farming. snails and slugs are primarily pests of seedlings and herbaceous plants. They are also serious pests of turfgrass seedlings and ripening fruits that are close to the ground, such as strawberries and tomatoes. Answer:(c)
Q.13
Commonly used in alcohol industry is ... [ BHU 2002]
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a) Saccharomyces
0%
b) Rhizopus
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c) Puccinia
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d) Penicillium
Explanation
Yeast species used in alcoholic fermentation are Saccharomyces cerevisiae (Brewer’s yeast), S. ellipsoidens (wine yeast), S. sake (Sake yeast) and S. pireformis (Ginger beer/ale yeast). Answer:(a)
Q.14
The large holes in 'Swiss cheese' are because of ... [ HPPMT 2011]
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a) Clostridium butylicum
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b) Trichoderma polysporum
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c) Propionibacterium shermanii
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d) Saccharomyces cerevisiae
Explanation
Swiss cheese has large holes produced by carbon dioxide given out by bacterium Propionibacterium sharmanii Answer:(c)
Q.15
In 1928, a scientist discovered the first effective antibiotic. Scientist and antibiotic are ...[ AIIMS 2000 ]
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a) Fleming -
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b) Fleming - Penicillin
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c) Waksman - Penicillin
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d) Waksman - Streptomycin
Explanation
Rene Dubois was first to produce an antibiotic named tyrothricin from Bacillus brevis. However, first antibiotic is generally associated with the name of Alexander Fleming when he discovered penicillin from Penicillium notatum. Answer:(b)
Q.16
Assertion: Nitrogen fixing enzyme in legume root nodules function at low oxygen concentration Reason: Low oxygen concentration is provided by leghaemoglobin ...[ AIIMS 2007]
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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 corrct explanation
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c) Assertion is true but reason is wrong
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d) Both are wrong
Explanation
Nitrogen fixing enzyme nitrogenase present in legume root nodules function at low oxygen concentration. Low oxygen concentration is provided by leghaemoglobin. Leghaemoglobin is known as scavenger of oxygen. Answer:(a)
Q.17
Organic farming is raising crops through use of ...[ AMU 2003]
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a) Biofertilizers
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b) Manures
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c) Resistant varieties
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d) All the above
Explanation
The key characteristics of organic farming include 1 Protecting the long term fertility of soils by maintaining organic matter levels, encouraging soil biological activity, and careful mechanical intervention; 2 Providing crop nutrients indirectly using relatively insoluble nutrient sources which are made available to the plant by the action of soil micro-organisms; 3 Nitrogen self-sufficiency through the use of legumes and biological nitrogen fixation, as well as effective recycling of organic materials including crop residues and livestock manures; 4 Weed, disease and pest control relying primarily on crop rotations, natural predators, diversity, organic manuring, resistant varieties and limited (preferably minimal) thermal, biological and chemical intervention; 5 The extensive management of livestock, paying full regard to their evolutionary adaptations, behavioural needs and animal welfare issues with respect to nutrition, housing, health, breeding and rearing; 6 Careful attention to the impact of the farming system on the wider environment and the conservation of wildlife and natural habitats. Organic farming is an agricultural system that uses fertilizers of organic origin such as compost manure, green manure, and bone meal and places emphasis on techniques such as crop rotation and companion planting. Biological pest control, mixed cropping and the fostering of insect predators are encouraged. Answer:(d)
Q.18
Which of the following is source of single cell protein ... [ HPPMT 2010]
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a) Bacillus thuringiensis
0%
b) Azospirillum
0%
c) Saccharomyces cerevisiae
0%
d) Methylophilus methylotrophus
Explanation
Answer:(d)
Q.19
Which is not used as biopesticide? ..[ CBSE 2009]
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a) Xanthomonas campestris
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b) Bacillus thuringiensis
0%
c) Tricoderma harzianum
0%
d) Nuclear polyhedrosis virus
Explanation
Xanthomonas campestris is an aerobic, Gram-negative rod known to cause the black rot in crucifers by darkening the vascular tissues. Remaining three are used as biocontrol agents for pathogens and pest. Answer:(a)
Q.20
The majority of Baculoviruses are used as biological control agents as ...[ HPPMT 2011]
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a) They are species - specific
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b) They have no negative impact on non-targets
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c) Beneficial insects are being conserved
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d) All the above
Explanation
Baculoviruses are pathogens that attack insects and other arthropods. The majority of baculoviruses used as biological control agents are in the genus Nucleopolyhedrovirus. These viruses are excellent candidates for species-specific, narrow spectrum insecticidal applications. They have been shown to have no negative impacts on plants, mammals, birds, fish or even on non-target insects. This is especially 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. Answer:(d)
Q.21
Azolla possesses symbiotic association with ...[ JKCMEE 2002]
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a) Rhizobium
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b) Nostoc
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c) Anabaena
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d) Azospirillum
Explanation
Answer:(c)
Q.22
Pasteurisation is heating at ... [ MPPMT 2001]
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a) 120° for 60 minutes
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b) 60° - 63° C for thirty minutes
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c) 70°C for 60 minutes
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d) 80° for 30 minutes
Explanation
Pasteurization is a process of preservation of milk, wine and other liquids by heating for a short period and then cooling rapidly. The most common method of milk preservation for 2-5 days is heating it at 72°C for 15 seconds or 63°C for 30 minutes. Answer:(b)
Q.23
During its formation, bread becomes porous due to CO2 released by ... [ CBSE 2002]
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a) Protozoans
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b) Bacteria
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c) Yeast
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d) Viruses
Explanation
A small quantity of baker’s yeast (Saccharomyces cerevisiae) is added to dough. The yeast acts on glucose to form bubbles of ethyl alcohol and carbon dioxide. This makes bread soft and spongy. Answer:(c)
Q.24
A free living nitrogen fixing cyanobacterium which also forms symbiotic association with Azolla is ...[ AFMC 2008]
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a) Anabaena
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b) Nostoc
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c) Chlorella
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d) Tolypothrix
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.25
VAM is important for ...[ Kerala 2000]
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a) Breaking of dormancy
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b) Phosphate nutrition
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c) Water uptake
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d) Decrease in yield
Explanation
Vesicular-arbuscular mycorrhiza (VAM) is formed by the symbiotic association between certain phycomycetous fungi and angiosperm roots. Vesicular Arbuscular Mycorrhizal (VAM) is a fungus which has the ability to dissolve the phosphates found in abundance in the soil. Apart from increasing the availability of phosphorus, VAM provides the plants with the necessary strength to resist disease germs and unfavourable weather conditions. Answer:(b)
Q.26
pH of vermiculture is kept at ... [ MHTCET 2010]
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a) Neutral
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b) Alkaline
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c) Acidic
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d) Highly alkaline
Explanation
The vermicomposting process was optimal at pH (6.5-7.7), temperature (19-25&dgeC) and moisture content (27.68-52.41%). pH should be closer to neutral. Answer:(a)
Q.27
Glucose fermentation by Yeast yields ... [ CBSE 1997]
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a) Ethanol + CO2
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b) Ethanol + H2O
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c) Methanol + CO2
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d) H2O + CO2
Explanation
Yeast produces enzyme zymase. Zymase converts glucose into ethanol and carbon dioxide Answer:(a)
Q.28
Conversion of milk to curd improves its nutritional value by increasing the amount of [NEET 2018]
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a) Vitamin D
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b) Vitamin A
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c) Vitamin B12
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d) Vitamin E
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:(c)
Q.29
A good producer of citric acid is …[NEET 2013]
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a) Aspergillus
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b) Pseudomonas
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c) Clostridium
0%
d) Saccharomyces
Explanation
Aspergillus niger can ferment sugar to produce citric acid. Citric acid is preservative and flavoring agent. It is also used in medicines, dyeing and inks. REFERENCE: NCERT class 12 biology page 183 Answer:(a)
Q.30
What gases are produced in anaerobic sludge digesters? ….[AIPMT 2014]
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a) Methane, Hydrogen Sulphide and O2
0%
b) Hydrogen sulphide and CO2
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c) Methane and CO2 only
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d) Methane, Hydrogen Sulphide and CO2.
Explanation
Methanogens work on organic acid produced in anaerobic sludge digesters. Methanogen produces methane, carbon dioxide, hydrogen sulphide. These mixture is called marsh gas or biogas. Answer:(d)
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