Page 1 - 2. Lesson notes- Bio- geo chemical cycles-1
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SAI International School
Subject- Biology
Chapter- Natural Resources
Subtopic- Bio- geo chemical cycles-1
Module- 33
Lesson Notes
Bio-geochemical cycles
A constant interaction between biotic (living) and abiotic (nonliving) components of the
biosphere makes a system and these flow of components form a cycle called biochemical cycle.
The biotic and abiotic components of the biosphere constantly interact through biogeochemical
cycles. The four important biogeochemical cycles are water cycle, nitrogen cycle, carbon cycle
and oxygen cycle.
Water cycle
The whole process in which water evaporates and falls on the land as rain and water flows back
into the sea via rivers is known as the water-cycle.
