Homework Practice

Printable assignment

Soil: Core Ideas

Start with Concepts

Question 1mcq

Which process is most responsible for changing large rocks into smaller soil particles over time?

A.Weathering

B.Photosynthesis in leaves

C.Melting of plastic

D.Condensation of steam

Question 2mcq

Why does soil formation usually take a very long time?

A.Soil forms only when glass melts.

B.Rocks break down slowly and organic matter builds up gradually.

C.All soil is made in one rainy day.

D.Plants directly change sunlight into soil.

Question 3mcq

A bare rock surface develops tiny cracks. Water enters the cracks and expands during cooling. What is likely to happen over many cycles?

A.The rock will instantly become pure clay.

B.The rock will stop interacting with air.

C.The rock may break into smaller pieces that can become soil particles.

D.The rock will turn into animal tissue.

Question 4mcq

A student says, “Soil is only powdered rock.” What important part is missing from this idea?

A.Soil contains no air at all.

B.Soil is made only of rainwater.

C.Soil cannot support living things.

D.Humus and living organisms are also important parts of soil.

Question 5mcq

Which observation best shows that organic matter is helping form fertile soil?

A.Dead leaves decay and mix with the top layer.

B.A mirror reflects sunlight.

C.A magnet attracts iron filings.

D.A plastic bottle floats in water.

Use the Ideas

Question 6mcq

Assertion: Soil formation is a slow natural process. Reason: Weathering and humus formation happen gradually. Which option is correct?

A.Both are true, but the reason does not explain the assertion.

B.Both assertion and reason are true, and the reason explains the assertion.

C.The assertion is true, but the reason is false.

D.The assertion is false, but the reason is true.

Question 7mcq

In a soil profile, which layer usually contains the most humus and many small living organisms?

A.Bedrock

B.Parent rock only

C.Topsoil

D.Deep unweathered rock

Question 8mcq

A vertical cut in the ground shows dark loose soil on top, lighter soil below and rock fragments deeper down. What is this vertical section called?

A.Food chain

B.Electric circuit

C.Respiratory path

D.Soil profile

Question 9mcq

Which sequence is most reasonable from top to bottom in a soil profile?

A.Topsoil, subsoil, parent material, bedrock

B.Bedrock, topsoil, leaves, clouds

C.Subsoil, topsoil, atmosphere, humus

D.Humus, oxygen, phloem, xylem

Question 10mcq

Why are many plant roots found mainly in the topsoil?

A.Topsoil has no organisms.

B.Topsoil has more humus, air, water and nutrients.

C.Topsoil is always solid rock.

D.Topsoil is completely dry everywhere.