question_answer 16)

  World's most problematic aquatic weed is (a) Azolla                             (b) Wolffia                          (c) Eichhornia                     (d) Trapa

Answer:

                  (c)Eichhornia (water hyacinth) has been introduced in India to check water pollution, as this weed absorbs mercury, cadmium, lead and nickel from sewage water. It is considered as world?s most problematic weed as it is on invasive species. If not controlled, water hyacinth covers the enitre pond or ake and impacts water flow. Blocks sunlight, acts as prime habitat for mosquito (vector) snails host for flatworm and starves water of oxygen.