1 Plants can only use 10% of the sun's energy 2 Energy in an ecosystem cannot be recyled 3 Tie movement of nitrogen in an ecosytem is the slowest among the nutrients in the biogeochemical cycle 4 The main reservoir of phosphorus is the atmosphere 5 The nitrogen-fixing bacteria change nitrogen gas into ammonium 6 Rhizobium is a kind of bacteria found in the nodules of legume plants 7 Carbon dioxide is one of the greenhouse gases that warm the earth 8 Organisms can take and use nitrogen in air 9 Eutrophication happens when water has excess nutrients 10 The organisms serve as the reservoir of the chemicals in the biogechemical cycle
