(b) J. C. Bose
     (c) Hargobind Khurana
     (d) S. Chandrashekar
Ans: (c)
168. Insulin was discovered by :
     (a) Alexander Flemming
     (b) Edmond Fischer
     (c) Dr. F G. Banting
     (d) Joseph E.Murray
Ans: (c)
169. For which one among the following diseases no vaccine is yet available? [CDS 2009]
     (a) Tetanus
     (b) Malaria
     (c) Measles
     (d) Mumps
Ans: (b)
170. The oral polio vaccine was discovered by : [MBA 1994]
     (a) Louis Pasteur
     (b) Robert Koch
     (c) Jonas Salk
     (d) Alexander Flemming
Ans: (c)
171. Which of the following theories was not proposed by Charles Darwin? [CDS 1991]
     (a) Natural selection
     (b) Survival of the fittest
     (c) Struggle for existence
     (d) Inheritance of acquired characters
Ans: (d)
172. The law of conservation of energy states that: [NDA 1993]
     (a) energy can be created as well as destroyed
     (b) energy can be created but not destroyed
     (c) energy cannot be created but can be destroyed
     (d) energy can neither be created nor destroyed
Ans: (a)
173. Which of the following can be used for biological control of mosquitoes? [Railways 1994]
     (a) Gammaxene
     (b) DOT
     (c) Gambusia
     (d) Oil
Ans: (c)
174. Which of the following are the pollutants that a traffic constable is likely to inhale? [CDS 1993]
          1) Carbon monoxide
          2) Lead
          3) Sulphur dioxide
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