Microbes in Human Welfare: MCQ Test

41. In cattle, where are methanogenic bacteria commonly found, playing an important role in cellulose breakdown and nutrition?

• Intestine
• Rumen (a part of stomach)
• Liver
• Kidneys

42. What is the primary raw material used for the generation of biogas, commonly called gobar gas?

• Plant waste from forests
• Industrial liquid effluent
• Human excreta from cities
• Cattle dung (gobar)

43. Which Indian organizations primarily spearheaded the development of biogas production technology in India?

• Indian Council of Medical Research (ICMR) and Council of Scientific & Industrial Research (CSIR)
• Indian Agricultural Research Institute (IARI) and Khadi and Village Industries Commission (KVIC)
• Defence Research and Development Organisation (DRDO) and Indian Space Research Organisation (ISRO)
• All India Institute of Medical Sciences (AIIMS) and Indian Institutes of Technology (IITs)

44. Biocontrol primarily refers to the use of:

• Chemical methods for controlling plant diseases and pests
• Biological methods for controlling plant diseases and pests
• Genetic engineering for pest resistance only
• Mechanical methods for physical pest removal

45. Which of the following insects are described as useful biocontrol agents to get rid of aphids and mosquitoes, respectively?

• Butterflies and Bees
• Ladybird beetles and Dragonflies
• Ants and Spiders
• Moths and Wasps

46. *Bacillus thuringiensis* (Bt) bacteria are widely used as microbial biocontrol agents to control which type of pests?

• Aphids
• Mosquito larvae
• Butterfly caterpillars
• Root-knot nematodes

47. How does the toxin produced by *Bacillus thuringiensis* specifically kill insect larvae?

• It repels them from the plants.
• It sterilizes them, preventing reproduction.
• The toxin is released in their gut, killing them.
• It enhances their growth, leading to overpopulation and collapse.

48. Which type of plant, developed through genetic engineering, is resistant to insect pests due to the introduction of *B. thuringiensis* toxin genes?

• Bt-rice
• Bt-wheat
• Bt-cotton
• Bt-corn

49. Which fungus is recognized as an effective biocontrol agent for several plant pathogens and is commonly found in root ecosystems?

• *Aspergillus niger*
• *Penicillium notatum*
• *Trichoderma*
• *Monascus purpureus*

50. *Baculoviruses* are pathogens that primarily attack which groups of organisms?

• Plants and mammals
• Birds and fish
• Insects and other arthropods
• Bacteria and fungi

51. The majority of baculoviruses used as biological control agents belong to which specific genus?

• *Streptococcus*
• *Trichoderma*
• *Nucleopolyhedrovirus*
• *Monascus*

52. *Baculoviruses* are considered excellent candidates for species-specific insecticidal applications because they have no negative impacts on:

• Plants
• Mammals, birds, and fish
• Non-target insects
• All of the above

53. What is the primary function of biofertilisers?

• To cause plant diseases
• To enrich the nutrient quality of the soil
• To control plant pests
• To produce antibiotics in soil

54. Which of the following are mentioned as the main sources of biofertilisers?

• Bacteria
• Fungi
• Cyanobacteria
• All of the above

55. The symbiotic association of *Rhizobium* bacteria with leguminous plants plays a crucial role in:

• Phosphorus absorption
• Fixing atmospheric nitrogen into organic forms
• Breaking down cellulose
• Producing organic acids

56. Which free-living bacteria mentioned in the text are capable of fixing atmospheric nitrogen in the soil, thus enriching its nitrogen content?

• *Lactobacillus* and *Streptococcus*
• *Aspergillus* and *Penicillium*
• *Azospirillum* and *Azotobacter*
• *Methanobacterium* and *Clostridium*

57. Many members of the genus *Glomus* form which type of symbiotic association with plants?

• Lichens
• Mycorrhiza
• Root nodules
• Algal blooms

58. What primary benefit does the fungal symbiont in mycorrhizal associations provide to the plant?

• Fixing atmospheric nitrogen
• Producing plant growth hormones
• Absorbing phosphorus from soil
• Protecting against insect pests

59. Besides phosphorus absorption, plants with mycorrhizal associations also show benefits such as:

• Increased susceptibility to pathogens
• Decreased tolerance to salinity
• Resistance to root-borne pathogens and tolerance to salinity/drought
• Reduced overall growth and development

60. Which of the following cyanobacteria are mentioned as being able to fix atmospheric nitrogen?

• *Anabaena*
• *Nostoc*
• *Oscillatoria*
• All of the above