Question

The circulation or cycling of elements in an ecosystem is known as
A. Geological cycling
B. Geo-chemical cycling
C. Biogeochemical cycling
D. Nutrient cycling

Answer 1

Hint: Biogenetic Nutrients are essential elements required by organisms for their body building and metabolism which are provided by earth. The amount of nutrients present in the soil at any given time is referred to as the standing state. It varies in different kinds of ecosystems and also on a seasonal basis.

Complete answer:
Whole living matter is made up of nutrients, either as structural components, biochemical as enzymes. An ecosystem has a limited supply of biogenetic nutrients in its abiotic environment. They are picked by producers and made part of organic matter. From producers the nutrients in the form of organic matter, pass to the higher trophic level. They are released back to the abiotic environment by decomposers acting on organic wastes and dead bodies of organisms. In this way the same nutrients repeatedly move through living and nonliving components of the ecosystem.
Now let us see the cycles given in options:
Geological cycling :- the collective cycling of tectonics , hydrological that is water cycling, cycling between rock along with nutrient cycle is termed as geological cycling . The process of formation of rock is included under rock cycling.
Geo – chemical cycling :- This cycle is mainly associated with the formation of earth. It is defined as the pathway by which chemical elements are taken at the surface and inside the crust of the earth.
Bio – geochemical cycling :- Circulation or exchange of biogenetic nutrients between the living and nonliving components is called biogeochemical cycle (at global scale).
Nutrient cycling :- movement of nutritive elements through various components of earth is called nutrient cycling. Thus this option is correct. The nutrients are circulated in every component of the ecosystem.

Our required answer is D) nutrient cycling.

Note: The whole of the biogenetic nutrients are not always in circulation. The nutrients exist in two states.
Reservoir pool :- nutrients are present in inactive form as for instance nitrogen gas in the atmosphere.
Cycling pool :- nutrients are present in active form. Nutrients are present in ionic form mostly.