Questions

Metabolism (from Greek: μεταβολή metabolē, "change") is the set of life-sustaining chemical transformations within the cells of organisms. The three main purposes of metabolism are the conversion of food/fuel to energy to run cellular processes, the conversion of food/fuel to building blocks for proteins, lipids, nucleic acids, and some carbohydrates, and the elimination of nitrogenous wastes.

In brief, the chemical processes that occur within a living organism in order to maintain life is called metabolism.

EI Hierro

Exide Life Insurance

The process which wherein an Ecosystem may renew itself is known as Ecological Succession.

The time scale may be decades or a million of years after a mass extinction. 

It may be achieve over a period of time.