Shireen likes to swim, play basketball and tennis, and visit the park. She is also active in art and the 4-H Club. Her father is her mentor because "he taught me to be a keen observer." Shireen would like to pursue a career in biomedical research. "I would like to learn more about how a particular disease occurs, what causes it, and how can we cure it," Shireen says.
Shireen's grandmother had diabetes, which kept her from enjoying sweets. Shireen wanted to explore the potential of Stevia, a shrub native to Paraguay that contains a natural diabetic-safe sweetener, as a dietary supplement. She discovered that large-scale production is tedious because Stevia seeds are slow to germinate.
Shireen took samples of shoot tips, nodes, roots, and leaves from mature plants. She placed the samples in synthetic plant culture media and added differing concentrations of the cytokinins BAP and TDZ, which are known to promote tissue growth. She grew the cultures for four weeks and then counted the amount of new growth on each. Shoot tips produced the highest number of new growths (shoots), ranging from 10-15 per sample. Shireen ultimately grew 75 plants in 14 weeks-all offshoots of one mature Stevia plant.
