While many teens admire rap singers, or pro athletes, these high school kids choose a Nobel Prize winning scientist as their role model.

"Science gives answers to the world," said Emily Barnett, 16, a junior at Highland High School.

Mario Capecchi, who received the Nobel Prize in Physiology or Medicine in 2007, spent an hour Tuesday night with a couple of dozen high school science students in the auditorium of the Salt Lake City Library.

The professor of human genetics and biology at the University of Utah then addressed an audience of several hundred adults who welcomed him with a standing ovation.

Capecchi, 71, is known for his pioneering work on the development of gene targeting in mouse embryo-derived stem cells. The technology allows scientists to create mice with mutations in any desired gene. The renowned discovery holds endless possibilities for development of treatments and cures for human disease.

The students sat quietly, hanging on to the award-winning professor's every word.

"Science is really fun," he told the teens. "Every day you have a puzzle, and someone is paying you to solve it. So you choose what you want to work on, and you proceed and do that."

Further, science is always changing, Capecchi said.

"The questions we are working on today are completely different from what we were working on five years ago — and will be completely different from what we're going to be working on five years from now. So you never get bored," he said.

"There are always new problems," Capecchi said. "You solve a problem and you generate 10 more questions. It's one of these things that keeps exploding."

The students gathered around the professor afterward for autographed copies of "The Power of Inquiry," which tells Capecchi's story of success, as well as details on his research.

Tony Dara, 15, a sophomore at Riverton High School, said he wants to pursue scientific research as a career.

"I think going into science would be really fun," he said. "I like the new things we can find in the future and how we can fix the problems."

The high school students peppered the professor with questions about his work and what it means. One teen asked if what has been discovered by experimenting with altering mouse genes can be used in humans.

"In theory, yes. But in practice, no — because we don't know enough," said Capecchi, who went on to address the issue as one of ethics.

For example, 1 percent of the population is resistant to AIDS, he said. So why not make that mutation in everybody and then the population would be resistant to AIDS?