試題詳解

51. Which of the following statements concerning biogeochemical cycles is NOT correct? 
(A) Plants and algae can use two inorganic forms of nitrogen: ammonium and nitrate.
(B) Photosynthesis by plants and phytoplankton removes substantial amounts of atmospheric CO2 each year. 
(C) The largest accumulations of phosphorus are in sedimentary rocks of marine origin. There are also large quantities of phosphorus in soils, in the oceans and in organisms.
(D) Under anaerobic conditions, nitrifying bacteria use NO3- in their metabolism instead of O2, releasing N2 in a process known as nitrification. 
(E) The major pathway for nitrogen to enter an ecosystem is via nitrogen fixation, the conversion of N2 by bacteria to forms that can be used to synthesize nitrogenous organic compounds.