Over the Past Century, Sagebrush Has Dramatically Expanded Its Range

question 48

Multiple Choice

Over the past century, sagebrush has dramatically expanded its range over the Colorado plateauʹs grasslands. This development has been attributed to the overgrazing of the areaʹs grasses by cattle and sheep. This example indicates that

• A) the relationship between sagebrush and grasses is mutualistic.
• B) sagebrush could not exist anywhere in the absence of cattle and sheep.
• C) grazing has no effect on the distribution of plants.
• D) sagebrush is the dominant competitor over grasses.
• E) the range of sagebrush is normally limited by competition with grasses.

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Definitions:

Pitch Diameters

The effective diameter of a screw thread, halfway between the crests and roots, used in measuring and specifying thread sizes.

Diametral Pitches

Diametral pitches refer to the number of teeth per inch of the diameter of a gear, which determines the size of the teeth and the pitch of the gear.

Ratchet Wheel

A wheel or gear with teeth cut in a way that allows motion in one direction only, often used in mechanisms requiring incremental movement.

Pawl

A mechanical component that engages with another component to prevent motion in one direction, or to drive a mechanism intermittently.