Ch 12Ecosystem — Class 12 Biology, concept-first.

An ecosystem is best understood as a functional unit of nature — living organisms interacting with each other and with their physical surroundings.

In earlier classes, you looked at the abiotic and biotic components of the environment individually — how they affect each other and their surroundings.

Productivity is the rate at which biomass is produced in an ecosystem. It tells us how fast energy is being captured and stored by organisms, and it is the foundation on which the entire food web rest…

Decomposition is the process by which the complex organic matter in dead plants and animals — leaves, roots, animal bodies, waste — is broken down into simpler inorganic substances.

The flow of energy is the single most important process that makes an ecosystem work. Every living organism needs energy to survive, grow, and reproduce, and that energy ultimately comes from one sour…

The relationship between organisms at different trophic levels — whether expressed in terms of number, biomass, or energy — takes the shape of a pyramid.

- Ecosystem structure: Every ecosystem has two interacting components — abiotic (physical factors like light, temperature, water, soil) and biotic (living organisms).

Higher-order thinking problems from the NCERT Exemplar.