3B: Soil

Multiple Choice

Why is soil considered essential for life on Earth?

• Because it provides nutrients and water to plants, supports all life, and is essential for human needs like food and oxygen.

• Because it only covers the Earth's surface and has no other function.

• Because it is used only for construction purposes.

• Because it is always dry and lifeless.

Multiple Choice

Which of the following terms is NOT commonly used to describe soil texture?

• Sandy

• Silt

• Clay

• Rocky

Multiple Choice

Which of the following statements about soil structure is correct?

• Soil structure describes the size of particles in the soil.

• Soil structure describes the way sand, silt, and clay particles are clumped together.

• Soil structure is not influenced by organic matter.

• Soil structure does not affect plant growth.

Multiple Select

Which of the following are types of soil structure?

• Granular

• Blocky

• Platy

• Fibrous

Multiple Choice

Which property of soil is responsible for the movement of air and water through it?

• Porosity

• Color

• Chemistry

• Texture

Open Ended

Explain how soil pH can affect plant growth and nutrient absorption.

Multiple Select

Which of the following are true about soil horizons?

• They are layers parallel to the soil surface.

• They are classified by physical features like color and texture.

• They are all the same in physical, chemical, and biological characteristics.

• They are labeled as O, A, E, B, C, or R.

Open Ended

Describe the differences between Horizon O, Horizon A, and Horizon E in soil layers.

Multiple Choice

Which soil horizon is known as the parent material and is made up of Earth's deposits, possibly produced by glaciers, lake sediment, or bedrock exposure?

• Horizon A

• Horizon B

• Horizon C

• Horizon R

Multiple Choice

Which of the following rocks is NOT typically found in the bedrock (R horizon) layer?

• Limestone

• Quartzite

• Basalt

• Clay

Multiple Choice

Which sequence correctly represents the order of soil horizons from the surface down to the bedrock?

• O, A, B, C, R

• A, O, B, C, R

• O, B, A, C, R

• O, A, C, B, R

Multiple Select

Which of the following are true about the O-horizon and A-horizon in a soil profile?

• O-horizon is decaying organic matter

• A-horizon is topsoil or dirt

• Both are considered 'traditional' dirt

• O-horizon is where plant roots grow

Multiple Choice

What are the main components that make up soil?

• Minerals, water, air, organic matter, and living organisms

• Only minerals and water

• Sand, rocks, and plastic

• Water, air, and metal

Open Ended

Explain why life does not exist in Horizon C of a soil profile. Use evidence from the soil profile to support your answer.

Open Ended

How does soil support life on Earth, and why is it essential for humans?

Open Ended

What is the difference between Horizon R and Horizon C in a soil profile?