A high school senior who cultivated populations of algae under her loft bed won first place and $100,000 in the Intel Science Talent Search on Tuesday night.

The contestant, Sara Volz, 17, of Colorado Springs, Colo., researched ways to create populations of algae cells with high oil content; this algae oil can be converted into an economically feasible biofuel. “It’s something she’s worked on for years, and that shows a certain passion and drive that you don’t always see in heavily mentored projects,” said David Marker, a mathematics professor at the University of Illinois at Chicago and the chairman of the judging panel. “And what really set her off was that she’s so well-rounded in all areas of science — I was able to ask her very advanced math questions that she answers easily.”

Second prize in the contest, $75,000, was awarded to Jonah Kallenbach, 17, of Ambler, Pa., for his project, “Characterizing and Identifying Interactions of Intrinsically Disordered Proteins.” Mr. Kallenbach’s research, in the burgeoning field of bioinformatics and genomics, focused on “disordered” regions in protein chains — areas with abnormal molecular structures. These areas eventually may serve as targets for newly developed drugs to treat diseases like breast cancer, ovarian cancer and tuberculosis.

Adam Bowman, 17, of Brentwood, Tenn., won third prize and $50,000 for research into less expensive ways to create ionized gases called plasmas, which have applications ranging from semiconductor manufacturing to nuclear physics. Current plasma sources are prohibitively expensive, and Mr. Bowman’s findings, which grew out of a tabletop plasma “gun” he built in his garage, could make the gases widely accessible to lower-budget institutions.