As Shown in the Following Graph,selected Intertidal Communities Along the Washington

question 48

Multiple Choice

As shown in the following graph,selected intertidal communities along the Washington coast changed when the sea star Pisaster ochraceus was removed.After 10 years,how did those communities compare to control communities?

• A) The communities were statistically indistinguishable from one another.
• B) Without sea stars, the total number of species declined.
• C) Other predatory sea stars replaced Pisaster.
• D) Some populations declined, but species diversity was unaffected.

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Definitions:

Depolarization

The process in which a cell's membrane potential becomes less negative, moving towards zero, typically initiating nerve impulses or muscle contractions.

Resting Potential

Electrical charge across the insulating cell membrane in the absence of stimulation; a store of potential energy produced by a greater negative charge on the intracellular side relative to the extracellular side.

Hyperpolarization

An increase in a cell's membrane potential, making it more negative and decreasing the likelihood of generating an action potential.

Semipermeable Membrane

A barrier that allows certain molecules or ions to pass through it by diffusion while blocking others, often used in osmosis.