Diatoms Are Algae Whose Silicon Dioxide-Containing Shells Are Useful Economically

question 3

Multiple Choice

Diatoms are algae whose silicon dioxide-containing shells are useful economically as

• A)filters.
• B)fertilizers.
• C)stabilizers.
• D)thickeners.

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Definitions:

Synclines

geological features formed by the downward folding of rock layers, with younger rocks in the core of the fold.

Cleavage

The tendency of a mineral to break along flat, defined surfaces as a result of its crystal structure.

Axial Surfaces

Imaginary surfaces that divide a fold as evenly as possible, extending through the apex of each fold in stratified rock.

Folds

Structures formed by the bending and warping of rock layers under pressure during geological processes.