When a Field in a Database Contains a Null Value

question 14

Multiple Choice

When a field in a database contains a null value, it means that ____.

• A) the field holds zeros
• B) the field holds spaces
• C) no data has been entered in the field
• D) the field holds asterisks

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Definitions:

Simple Diffusion

The movement of molecules from an area of higher concentration to an area of lower concentration without the need for energy input or assistance of membrane proteins.

Cellular Membrane

The cellular membrane, or plasma membrane, is the biological membrane that separates the interior of all cells from the outside environment, controlling the movement of substances in and out of cells.

Exocytosis

The active transport of materials out of the cell by fusion of cytoplasmic vesicles with the plasma membrane. Compare with endocytosis.

Plasma Membrane

The semipermeable membrane surrounding the cytoplasm of a cell, responsible for controlling the passage of substances in and out of the cell.