In DB 11x the alerts were changed to Incidents so your Grid Control will show them listed under the Incident category. Go to All Metrics -> Expand Incidents, and you'll see many categories. This replaces the "generic alert" from 10g. You can see more info in the docs at http://docs.oracle.com/cd/E24628_01/em.121/e25160/oracle_database.htm#autoId165.
10g databases will continue to have the Generic Alert format.