An identification of students’ interests in biology can help teachers better engage their pupils and meet their needs. To this end, over 28,000 self-generated biological questions raised by students from kindergarten through graduate school were analyzed according to age and gender. The sample demonstrated a dominance of female contributions among K- 12 students. However, girls’ interest in submitting questions dropped as they grew older. Topics popular among different age groups of males and females were identified, and the development of interest was described. Ways in which students’ interests can be incorporated into a standard-based curriculum are discussed, mainly as a trigger for the learning of less popular subjects which are required by the curricula.