Soil Homework

What is soil made of?

Which element is humus especially rich in?

• Oxygen

• Carbon

• Nitrogen

• Tungsten

What do weathering and erosion have in common?

• They both occur underground

• They both involve the application of heat and pressure

• They both break down rocks and minerals

• They both bring about chemical changes in rocks and minerals

Which of these things is a primary ingredient of humus?

• Dead plant material

• Rocks from the earth's crust

• Minerals

• Metals

What effect do plants' roots have on rock?

• They hold it together

• They weather it

• They cause it to undergo chemical changes

• They break it apart

Which of the following terms best describes the processes of weathering and erosion?

• Instantaneous

• Gradual

• Rapid

• Insignificant

Which plants are usually the first to live in soil?

• Simple Plants

• Trees

• Plants that can support insect life

• Flowers

How would you compare young soil to soil that has been around a long time?

• Young soil can hold more water than old soil

• Young soil is rockier than old soil

• Young soil is thicker and grainier than old soil

• Young soil has less organic matter than old soil

Why is topsoil darker than the other levels of soil?

• It contains more organic matter

• It contains all the darker-colored minerals

• It contains volcanic rock

• It contains bits of burned trees

What exactly is bedrock?

• Any organic rock or mineral

• Rock that lies underwater

• Rock that has not been weathered

• Especially soft rock