Q42. Name the microorganisms which can fix atmospheric nitrogen in the soil.
Q43. Why sugar is used as preservative?
Q44. Which microorganism is used for commercial production of alcohol, wine and acetic acid (vinegar)?
Q45. Name some commonly known antibiotics which are made from fungi and bacteria.
Q46. What are the harmful effects of microorganisms on plants?
Q47. Name some diseases caused by virus.
Q48. How does food become poisonous?
Q49. How can we prevent the spread of hepatitis B?
Q50. How can food be preserved by adding oil and vinegar?
Q51. How milk is turned into curd?
Q52. How does common cold spread?
Q53. Why is tuberculosis considered as infectious disease?
Q54. What causes tuberculosis and how is it spread?
Q55. What are biological nitrogen fixers?
Q56. How can cholera be prevented?
Q57. What are pathogens?