Integrated Science - Ch. 21 Test Review

Soil is a mixture of weathered rock, mineral fragments, water, air and ____.

• sand
• deayed organic matter
• moss
• clay

The layer of soil that contains the most organic material is called the ____ horizon.

• A
• B
• C
• D

All of the following cause mechanical weathering EXCEPT ____.

• ice
• tree roots
• burrowing animals
• carbonic acid

Litter often covers the ____ horizon.

• A
• B
• C
• D

Mechanical weathering is more rapid in a ____ climate.

• dry
• hot
• cold
• humid

The organic matter in humus is made of ____.

• dead worms
• stems
• roots
• all of these

The rate of weathering depends upon the area's ____.

• oxygen
• climate
• water
• soil

The rock and mineral fragments in soil come from rock that has been ____.

• blasted
• carved
• weathered
• chmically treated

Soils in ____ contain little organic material and are thin.

• tropical areas
• deserts
• prairies
• temperate forests

Plants cannot grow without ____.

• rocks
• soil
• moss
• pesticides