Pat Owen is chair of the National Grizzly Society, which maintains a database of all grizzly bears within the United States. One table will store 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 will contain data that link each grizzly bear to its male and female parents by means of their registration numbers. The primary key in the second table is
◦ name.
◦ birth date.
◦ the same as the primary key in the first table.
◦ a combination of primary keys in the first table.
