CBSE Class 9 Answered

But in bio geochemical cycles  after the death of that particular organism, excreta minerals thus, released are reutilised by the plants and being recirculated in the system. Thus the nutrients rotates in a cyclical manner in bio geochemical cycles.

b.The nitrogen cycle is said to be an ideal cycle in the biosphere because there is no loss of nitrogen and the amount of nitrogen remains constant which follows the law of conservation of matter. In other biogeochemical cycles, there ¡s loss of energy or loss of matter.