Two Fundamental Concepts About the Ion Channels of a "Resting

question 38

Multiple Choice

Two fundamental concepts about the ion channels of a "resting" neuron are that the channels

• A) are always open, but the concentration gradients of ions frequently change.
• B) are always closed, but ions move closer to the channels during excitation.
• C) open and close depending on stimuli, and are specific as to which ion can traverse them.
• D) open and close depending on chemical messengers, and are nonspecific as to which ion can traverse them.
• E) open in response to stimuli, and then close simultaneously, in unison.

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Definitions:

Accrual Accounting

An accounting method where revenues and expenses are recorded when they are earned or incurred, regardless of when cash transactions occur.

Hurdle Rate

The minimum rate of return on a project or investment required by a manager or investor.

Weighted Average Cost

A method of calculating the total cost of goods available for sale, considering the weighted average of all goods.

Payback Period

The amount of time it takes for an investment to generate an amount of income or cash equal to the cost of the investment.