Question

What is an ecosystem? Describe the components of an ecosystem.

Hint:

Abiotic (physical/chemical factors) + biotic (producers, consumers, decomposers).

Answer 1

Step 1: Define ecosystem (1 mark):
An ecosystem is a functional unit of nature in which living organisms (biotic components) interact among themselves and with their non-living physical environment (abiotic components), forming a self-sustaining system with continuous exchange of energy and matter.

Step 2: Describe the abiotic components (2 marks):
Abiotic components include physical factors like temperature, light, rainfall, soil, and inorganic and organic substances present in the environment (e.g. water, carbon dioxide, oxygen, minerals, humus) that support and constrain the living organisms.

Step 3: Describe the biotic components (2 marks):
Biotic components are classified by their functional role: producers (autotrophic green plants and some bacteria/algae that fix solar energy through photosynthesis), consumers (heterotrophic organisms that depend on producers directly or indirectly for food, further divided into primary, secondary and tertiary consumers), and decomposers (bacteria and fungi that break down dead organic matter, releasing nutrients back into the abiotic pool).

Final Answer:
An ecosystem is the functional unit combining a physical (abiotic) environment with the living (biotic) community of producers, consumers and decomposers, linked through continuous energy flow and nutrient cycling.