Soil: An Important Natural Resource for Life

Soil is a crucial resource for all living organisms, providing a medium for plant growth and a habitat for microorganisms. It supports human needs for food, clothing, and shelter. Soil formation is a slow process that began with the weathering of rocks. Over time, organic matter mixed with weathered rock particles, creating fertile soil. Soil is composed of various layers, known as horizons, each with distinct characteristics. The topsoil is rich in humus and minerals, while deeper layers contain more compact materials. Understanding soil's composition and formation helps us appreciate its vital role in sustaining life.

Why is soil considered an essential resource for humans?

• It is a habitat for marine life.

• It provides a medium for plants to grow.

• It is a source of minerals for mining.

• It is used to generate electricity.

What natural process leads to the formation of soil from rocks?

• Volcanism

• Sedimentation

• Weathering

• Erosion

Which component of soil is responsible for its fertility?

• Gravel

• Sand

• Clay

• Humus

What determines the mineral content of soil?

• The presence of animals

• The amount of rainfall

• The type of rock weathered

• The type of vegetation

Which layer of soil is known as the topsoil?

• Bedrock

• A horizon

• B horizon

• C horizon

What is the main characteristic of the B horizon?

• It contains large rocks.

• It is rich in minerals.

• It is softer than the A horizon.

• It is rich in humus.

Which organisms are commonly found in the A horizon?

• Reptiles and insects

• Worms and beetles

• Birds and mammals

• Fish and amphibians