What Is a Primary Key

question 45

Multiple Choice

What is a primary key?

• A) A field (or group of fields) that uniquely identifies a given entity in a table.
• B) A primary key of one table that appears as an attribute in another table and acts to provide a logical relationship between the two tables.
• C) Characteristics or properties of an entity.
• D) A field (or group of fields) that uniquely identifies a given attribute in a table.

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Definitions:

Growth Cones

Dynamic, actin-supported extensions of a developing or regenerating neurite seeking its synaptic target.

Glial Cells

Cells within the central and peripheral nervous system, not of neuronal origin, that offer both support and protection to neurons.

Tropic Molecules

Substances that guide the growth or movement of developing cells or parts of an organism in response to certain stimuli.