LIVERMORE -- Question for you: What organelle functions to isolate a human cell's chromosomes from the cytoplasm?

Sorry, your time is up. Good thing you weren't on one of the 24 middle school teams that competed Saturday in the U.S. Department of Energy Regional Science Bowl at Las Positas College.

If you had been, well, you wouldn't have been asked the question above. That's a sample question from the National Science Bowl website. (Sample answer: nucleus, of course.) Officials at Saturday's event -- volunteers from Sandia National Laboratories -- declined to divulge a real question for fear it might find its way into the public domain and taint a future competition.

When it comes to fun and games, the Science Bowl is serious business. And, judging by the smiles on the students' faces, vice versa.

The four-person teams, culled from middle schools in Alameda, Contra Costa, San Joaquin, Sacramento and Yolo counties, began the day competing head-to-head in a round-robin format in classrooms on the Las Positas campus. The students, each armed with a beeper, were read short answer or multiple-choice questions based on math, earth science, space science, biology, chemistry, physics or energy. Contestants buzzed in to answer, sometimes after extended whispering confabs with their teammates.

The spoils: An expense-paid trip to Washington, D.C., to compete in the national championships April 25-29.

The victor: For the second consecutive year, powerhouse Hopkins Junior High of Fremont edged runner-up The Dorris-Eaton School of Walnut Creek 108-96 in a nip-and-tuck final contest. It won't exactly be unchartered waters for Hopkins, which has won two of the past four national middle school Science Bowls.

But trips and trophies weren't the only rewards for the taking Saturday. Consider the team from Pittsburg's Hillview Junior High, which was appearing in its first regional competition.

"My poor students; I know that they are nervous," Hillview teacher Sarah Tuico said during a break in the morning session as her students chattered excitedly just a few feet away. "But I think it's building a lot of character and a lot of leadership. I'm really proud. We're increasing in points each round. They're in great spirits. They're getting lots of good experience and confidence."

Tuico said eight students tried out for the five-person team (including an alternate). They began practicing for the event in September, meeting for two 35-minute sessions per week. They discovered Saturday that the competition isn't just about knowledge, it's also about understanding the strategy of the game.

"We didn't have beepers" with which to practice, she said. "But they said we can borrow them for next time, so we're definitely going to do that. I look forward to coming back next year for sure."

Contact Gary Peterson at 925-952-5053. Follow him on Twitter at Twitter.com/garyscribe.