OMAHA, Neb. (AP) — More than 500 students from sixth- to 12th grades across the Midwest area are competing this weekend in the 14th annual Regional Science Olympiad at Omaha's Henry Doorly Zoo and Aquarium.

The all-day event Saturday has students competing in rigorous challenges in anatomy and physiology, astronomy, earth science, food science, forensics, genetics, geology, mechanical engineering, physics and technology. The event was started by the zoo in 2005 as an outlet for students to advance to the Nebraska Science Olympiad in April.

Students representing about 45 schools and teams in the Midwest are participating.