Soil - 1 - Free MCQ Practice Test with solutions, Class 3 Science

• Minerals: Essential nutrients for plants, derived from the weathering of rocks.
• Organic Matter: Decomposed plant and animal materials that enrich the soil and support microbial life.
• Air: Spaces between soil particles hold air, which is crucial for root respiration.
• Water: Vital for plant growth, it dissolves nutrients and facilitates their uptake by plants.

Clay is the finest grain. Sand is the coarse grain and silt comes between clay and sand.

• Topsoil: This is the uppermost layer, rich in organic matter and nutrients, making it essential for plant growth.
• Subsoil: Located beneath the topsoil, it contains minerals and less organic material. It holds water and nutrients that plants can access.
• Parent Material: The deepest layer, consisting of weathered rock or sediment. It provides the minerals that contribute to the soil's composition.

The water holding capacity is the highest in clayey soil.

Sandy soil does not retain water and is usually found in deserts and beaches.

Lemur is an animal that usually stays on trees, all other options are found in the soil.

Birds do not contribute in the formation of soil.

Plants get their nutrients from the uppermost layer i.e. Top soil.
Weathered fragments: the process of breaking down large or bigger rocks into smaller minerals and then into the smallest particles to form soil.

Layer B is Subsoil. The layer is below the topsoil and above the bedrock.

Gravel is the odd one out as all the other three are part of the loamy soil.