The National Grizzly Society maintains a database of all grizzly bears within Canada. One table stores the name, birth date, and other characteristics of all of the grizzly bears that have been registered. Each grizzly bear is uniquely identified by a registration number. A second table contains data that link each grizzly bear to its male and female parents by means of their registration numbers. The primary key in the first table is:

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BlackTom AI · Accepted Answer

The question presents two related tables in a database design scenario involving grizzly bears. The first table stores each bear's core attributes (name, birth date, etc.) and uses a unique registration number as its primary key. The second table links bears to their male and female parents by storing registration numbers that reference bears in the first table. With that context in mind, let's evaluate each option.

Option 1: 'name.' This is incorrect as the primary key of the first table is not a name field. Primary keys must uniquely identify a record, and names are not guaranteed to be unique across all bears (two bears could share the same name). Therefore, name cannot reliably serve as the primary key for the first table.

Option 2: 'birth date.' This is also incorrect. Birth dates are not unique identifiers for individual bears; multiple bears could share the same birth date, and even a single bear cannot be uniquely identified by birth date alone. Primary keys require uniqueness and immutability, which birth date does not guarantee.

Option 3: 'the primary key in the second table.' This is not aligned with the notion of the first table's primary key. The first table has its own primary key (the registration number). The phrase 'the primary key in the second table' would describe a key belonging to the second table, not the first. The question asks specifically for the primary key of the first table, so this option mislabels which table's key is being referenced.

Option 4: 'a foreign key in the second table.' This option reflects the relational design described: the second table stores references to bears in the first table via their registration numbers. Those registration numbers act as foreign keys in the second table, pointing to the primary key of the first table. In other words, the linkage from the second table back to the first is established through foreign keys that reference the first table's primary key. This relationship is consistent with common database normalization practices where a child table (second table) contains foreign keys that reference the parent table's (first table) primary key.

Overall, option 4 correctly describes the role of the first table's primary key in this two-table schema, while options 1 and 2 fail due to non-unique or non-identifying properties, and option 3 confuses which table's key is being referenced. The reasoning above highlights the core ideas: unique identification in the first table, the use of that key as a reference from the second table, and the typical parent-child foreign-key relationship in relational databases.

COMM_V 335 101 102 2025W1 FINAL EXAM - 2025W1 - Requires Respondus LockDown Browser

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Question at position 11 In ERDs, the primary key isAn attribute that cannot be modified after it is setAn attribute that uniquely identifies each record in a database tableA graphical symbol indicating the connection between entitiesA set of optional attributes linked to an entity

A database table usually has a(n) _______________________ that uniquely identifies each row in the table.

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