AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
Soil is called a living system because it supports various living organisms, contains organic material (humus), and involves biological processes like decomposition by decomposers that are essential to its formation and functioning.
Source: Soil as a Resource, Chapter 1
The examiner expects you to mention: (1) presence of living organisms, and (2) biological/organic processes occurring within soil. One precise sentence covering both points is sufficient for 1 mark. Avoid listing soil types or formation factors — those are irrelevant here.