In this paper, we report findings based on voluntary and anonymous surveys completed by post high school students on bioscience education trajectories -- summer undergraduate research fellows (SURF students) who were doing research at UT Southwestern Medical Center during 2014-2019 and biology undergraduates who participated in the 2019 Howard Hughes Medical Institute annual Science Education Alliance (SEA) summer symposium. About 25% of the students who completed surveys indicated that they had participated in high school science fair, but more than half attended high schools where science fairs were unavailable. Effectively, therefore, 6 out of every 10 students participated in science fair if available. Students who could have participated in high school science fair but chose not to do so identified not enough time and coming up with their project idea as major reasons why not. About half the SURF students favored requiring non-competitive science fair regardless whether they themselves had participated in science fair. On the other hand, less than 1 in 5 thought that competitive science fair should be required. Introduction to the scientific process and general learning were mentioned most frequently as the reasons to require non-competitive science fair; these reasons were mentioned rarely in connection with competitive science fair. Unlike the national cohort of high school students we surveyed previously, who mostly did science fair in 9th and 10th grades, SURF students participated in science fair throughout high school and were twice as likely as high school students to have carried out science fair more than once. Re-evaluation of the national cohort of high school students based on grade level showed that for those doing science fair in 12th grade, about 80% indicated that they were interested in careers in science or engineering up from 50% in 9th grade, and those uninterested in a career dropped from 35% to 3% over the same period. In conclusion, our findings show that participation of undergraduate bioscience majors in high school science fair occurs far more frequently than recognized previously. We emphasize the importance of incentivizing rather than requiring science fair participation and the potential value of developing non-competitive science fairs, especially for students in 9th and 10th grades.