Soil is a complex mixture of stones, water, dead plants, and microorganisms. It forms over years as rock weathers into particles, allowing air and water to fill spaces. Plant roots absorb water, and animals live in the soil. When plants and animals die, they become organic matter, which microorganisms decompose into humus. Humus enriches soil, aiding water absorption and mineral release. Soil has layers: topsoil rich in humus, subsoil of clay and sand, and bedrock, which breaks down to form soil, creating habitats for creatures like naked mole rats.

What are the primary components that make up soil?

• Sand, clay, and gravel

• Stones, water, and dead plants

• Rocks, metal, and glass

• Minerals, air, and plastic

How do plant roots contribute to the soil ecosystem?

• They break down rocks into soil

• They absorb water and nutrients

• They produce oxygen for animals

• They create new microorganisms

What is humus and why is it important?

• A microorganism that breaks down plants

• A mineral found in subsoil

• Organic matter that helps soil retain water

• A type of soil layer

Which layer of soil is most abundant in humus?

• Weathered rock

• Bedrock

• Subsoil

• Topsoil

What is the role of bedrock in soil formation?

• It provides minerals to the topsoil

• It breaks down to form soil over time

• It acts as a barrier to water

• It supports plant roots