Answer Key of BHU PET Applied Microbiology 2014 (Part 1)

Answer Key of BHU PET Applied Microbiology 2014

Q1. Biochemical oxygen demand (BOD) of the medium depends on 

(1) Amount of micronutrients present in the medium

(2) Amount of microbial load present in the medium

(3) Amount of organic matter present in the medium

(4) Amount of oxygen dissolved in the medium 

Q2. In transgenic B.t. cotton, the product of incorporated bacterial gene is 

(1) Theta exotoxin

(3) Delta exotoxin 

(2) Beta exotoxin

(4) Delta endotoxin 

Q3. Which of the following statement about fungi is false 

(1) They are all heterotrophs

(2) They contain membrane bound nucleus

(3) They require organic molecules for energy source

(4) They fix atmospheric nitrogen 

Q4. In ‘Aquaguard’ used for purification of water, the microbes are  killed under ultraviolet radiations due to:

(1) Dimerization of nitrogen bases in the DNA of microbes

(2) Breakage of peptide bonds in the microbial proteins

(3) Generation of free radicals in the water

(4) Destruction of organic matter in water. 

Q5. Mushroom is a: 

(1) Lichen

(3) Alga 

(2) Plant

(4) Fungus 

Q6. GMO’ is the term used to refer: 

(1) Gene map of organism

(2) Gene manipulation and optimization

(3) Genetically modified organism

(4) Genetic marker of organism 

Q7. Natural microflora is used in the preparation of:

(1) Curd 

(2) Tempeh

(3) Idli 

(4) Beer 

Q8. An example of primary producer organism is: 

(1) Amoeba 

(2) Plasmodium

(3) Escherichia 

(4) Spirulina. 

Q9. In a continuous culture of bacterium, the organism is maintained in:

(1) Lag phase 

(2) Log phase

(3) Stationary phase 

(4) Decline phase 

Q10. The total carbon content of the medium in which aerobic bacterium  is growing continuously

(1) Inarcases

(2) Decreases ‘

(3) Remains constant

(4) First increases and then decreases 

Q11. Among waters from different sources, maximum BOD is shown by – 

(1) Municipal sewage 

(2) Drinking water

(3) Distilled water 

(4) River water 

Q12. Which of the following will increase the dissolved oxygen content of  the fermentation medium by purging air through sparger

(1) Increased air flow rate

(2) Reduced size of the air bubbles

(3) Increased revolutions of the impeller

(4) All the above 

Q13. The relationship between growth rate and generation time of a bacterium is

(1) Inverse 

(2) Direct

(3) Unrelated 

(4) Proportion 

Q14. When Escherichia coli is inoculated in the medium containing both  glucose and lactose, which of the following utilization patterns will be observed?

(1) Glucose will be utilized first and lactose thereafter

(2) Lactose will be utilized first and glucose thereafter

(3) Both will be simultaneously utilized

(4) The one having higher concentration will be utilized first. 

Q15. Which among the following media will actually savor the growth of certain organisms while suppressing the growth of others?

(1) Differential medium 

(2) Synthetic medium

(3) Natural medium 

(4) Selective medium 

Q16. Which of the following bacteria shows green metallic sheen on an eosin-methylene blue agar plate?

(1) Gram negative enteric

(2) Gram positive enteric

(3) Gram positive 

(4) Gram negative 

Q17. In which of the following medium does an observable change taķes place when a biochemical reaction occurs?

(1) Differential medium 

(2) Complex medium

(3) Synthetic medium 

(4) Selective medium

Q18. The organism used for bioassay of antibiotic is: 

(1) Sensitive to that antibiotic

(2) Resistant to that antibiotic

(3) A mutant that degrades antibiotic

(4) The one that synthesizes that antibiotic

Q19. Mycoparasitic fungus used for control of fungal pest is: 

(1) Rhizoctonia solani

(2) Trichoderma viride

(3) Aspergillus niger

(4) Aspergillus flavus. 

Q20. Sodium thioglycolate is incorporated into nutrient medium for the  growth of which one of the following groups?

(1) Aerobic bacteria 

(2) Anaerobic bacteria

(3) Halophilic bacteria 

(4) Thermophilic bacteria 

Q21. Resistance to antibiotics in the bacteria is carried in the: 

(1) Introns 

(2) Exon

(3) Plasmid 

(4) Heteromeric. 

Q22. The characteristic that does not affect the death rate of microbial population under adverse condition is:

(1) Initial population of microbes.

(2) Exposure time to adverse condition

(3) Susceptibility of organism to adverse condition

(4) Severity of adverse condition. 

Q23. In a refrigerator, the spoilage of food is prevented because: 

(1) The associated microbes are killed

(2) The microbial activity is arrested

(3) Food is stored at lower temperature

(4) No light is available in the closed refrigerator. 

Q24. Resistance to beta-lactam antibiotics in bacteria is due to the  capacity to synthesize an enzyme

(1) Penicillinase 

(2) Penicillin acylase

(3) Penicillin amidase 

(4) Penicilloic acid. 

Q25. At the center of composting pit, the surviving microbial population  predominantly consists of

(1) Psychrophiles 

(2) Mesophiles

(3) Thermophiles 

(4) Halophiles 

Explanation: Under optimal conditions, composting proceeds through three phases: 1) the mesophilic, or moderate-temperature phase, which lasts for a couple of days, 2) the thermophilic, or high-temperature phase, which can last from a few days to several months, and finally, 3) a several-month cooling and maturation phase.

Q26. During the production of semisynthetic penicillin, an enzyme required for breakdown of 6-amino-penicillanic acid moiety benzyl penicillin is:

(1). Penicillinase 

(2) Penicillin acylase

(3) Aromatase 

(4) Penicillin kinase. 

Q27. The process that reduces the number of potential pathogens on an inanimate object until they no longer represent a disease hazard is called:

(1) Sterilization 

(2) Disinfection

(3) Antisepsis 

(4) Decimal reduction 

Q28. Which of the following best describes how cells in a population die when exposed to an antimicrobial agent?

(1) It depends on the species

(2) It depends on the antimicrobial agent.

(3) The cells all die at once

(4) The cells in a population die exponentially. 

Q29. Which of the following physical treatments causes damage to bacterial cells by production of free radicals?

(1) Ultraviolet light 

(2) Gamma ray irradiation

(3) Microwave irradiation

(4) Heat 

Q30. Which of the following would be the fastest way to kill endospores? 

(1) Autoclave at 121 degrees Celsius

(2) Tincture of soap

(3) Hot air oven at 180 degrees Celsius

(4) Clorox solution 

Q31. The time it takes to kill 90% of a population of bacteria under  specific conditions is defined as

(1) Generation time

(2) Thermal death time

(3) Decimal reduction time

(4) Half life time 

Q32. Which one of the following is a fungal sexual spore? 

(1) Basidiospore 

(2) Blastospore

(3) Chlamydospore 

(4) Conidiospore 

Q33. The exotoxin produced by Clostridium botulinum is due to: 

(1) Lytic infection 

(2) Virulent infection

(3) Lysogenic conversion

(4) Transduction 

Q34. Infections acquired in a hospital are called as 

(1) Critical infection

(2) Fastidious infections

(3) Nosocomial infections

(4) Opportunistic infections, 

Q35. Which of the following diseases are caused by bacteria? 

(1) Pneumonia, Tetanus and Diabetes 

(2) Pneumonia, Tetanus and Scurvy 

(3) Typhoid, Measles and Cholera 

(4) Typhoid, Pneumonia and Tuberculosis 

Q36. Downstream processing is best defined as: 

(1) Procedure adopted to the recovery of product from broth

(2) Conversion of laboratory procedure to an industrial process

(3) Removal of broth from fermentation vessel

(4) Flow of medium from higher to lower level. 

Q37. Biochemical oxygen demand of the medium is directly proportional to 

(1) The number of microorganisms present in it.

(2) Amount of oxygen dissolved in the medium 

(3) Amount of organic matter present in the medium

(4) Amount of micronutrients present in the medium 

Q38. In transgenic B.t. cotton, the product of incorporated bacterial gene is

(1) Theta-exotoxin 

(2) Beta-exotoxin

(3) Delta-exotoxin 

(4) Delta-endotoxin 

Q39. Mycoparasitic fungus used for the control of fungal pests on crop plants is.

(1) Rhizoctonia solani 

(2) Trichoderma viride

(3) Aspergillus flavus 

(4) Rhizopus niger 

Q40. For quantitative estimation of total soil bacteria, which of the following is an appropriate method?

(1) Serial dilution and plating

(2) Direct plating

(3) Enrichment culture plating

(4) Direct counting of bacteria under microscope 

Q41. Which of the following antibiotics has a beta-lactam ring? 

(1) Cephalosporin 

(2) Polymyxin

(3) Streptomycin 

(4) Bacitracin 

Explanation: β-lactam antibiotics (beta-lactam antibiotics) are antibiotics that contain a beta-lactam ring in their molecular structure. This includes penicillin derivatives (penams), cephalosporins (cephems), monobactams, carbapenems and carbacephems.

Q42. When purged in water, which of the following will have the largest surface area per unit volume of the air?

(1) Bubbles having diameter of 1 millimeter

(2) Bubbles having diameter of 2 millimeter

(3) Bubbles having diameter of 3 millimeter

(4) Bubbles having diameter of 4 millimeter 

Q43. Which of the following techniques gives a viable count?

(1) Most probable number

(2) Direct microscopic count

(3) Turbidimetry

(4) Dry weight determination 

Q44. Sodium thioglycolate is incorporated into nutrient medium for the growth of which of the following groups?

(1) Aerobic bacteria 

(2) Anaerobic bacteria

(3) Halophilic bacteria 

(4) Thermophilic bacteria 

Q45. Lactobacilli contribute to food production by 

(1) Altering flavour

(2) Enhancing nutrient value

(3) Reducing contamination and retarding spoilage

(4) All the above 

Q46. There are three basic tests to detect coliform bacteria in water, presumptive, confirmed, and completed tests. The following apply to these tests except

(1) They are performed sequentially

(2) They detect lactose fermentation by acid and gas production

(3) They use MPN method

(4) They determine the dry cell weight of coliforms in the sample 

Q47. Which of the following biological preparations contain viable attenuated organisms?

(1) B.C.G. vaccine 

(2) Diphtheria antitoxin

(3) Tetanus antitoxin 

(4) Old tuberculin 

Q48. A causative agent of ringworm is

(1) Trichophyton rubrum

(3) Candida albicans 

(2) Blastomyces dermatitidis

(4) Sporothrix schenckii 

Q49. Which of the following characteristics is common to both pseudomonads and Escherichia coli?

(1) They both produce endospores

(2) They are both Gram negative rods

(3) They are both enteric bacteria

(4) They are both strict anaerobes . 

Q50. After a virus has attached and penetrated into the host coll, no virus can be detected until the host cell is lysed. This stage of viral replication is called as

(1) Latent period

(2) Penetration

(3) Budding 

(4) Lysis