Cepheid Variables Are Stars Whose Brightness Varies in a Predictable

question 69

Multiple Choice

Cepheid Variables are stars whose brightness varies in a predictable manner so that the absolute magnitude of the star can be determined, and this allows the ___________of the star to be determined.

• A) distance from Earth
• B) size
• C) direction of motion
• D) composition
• E) velocity

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Definitions:

Sodium-Potassium Pump

A membrane-bound transporter enzyme present in many cell (plasma) membranes that pumps sodium out of cells while pumping potassium into cells, thus maintaining the concentration and electrical gradients of these ions.

Endocytosis

Process by which a cell takes in a small amount of extracellular fluid (and its contents) by the ballooning inward of the plasma membrane.

Exocytosis

Process by which a cell expels a vesicle’s contents to extracellular fluid.

Entropy

A measure of disorder or randomness in a system, often associated with the second law of thermodynamics.