How the Celery Challenge Works

This module is framed as a challenge to cause and explain the most extreme bending in celery petioles (stalks), designed as two guided inquiries and an open inquiry with introductory and concluding class discussions.

In the introductory discussion, students imagine a real world scenario about preparing celery the day before a party. Working in small teams, students observe and try to explain two phenomena: (1) the bending of celery stalks soaked in liquids and (2) the concentration of dye in certain cells within celery stalks placed in colored water. Exploring the forms and functions of different tissues and cells allows students to build an understanding of structure-function relationships in biology and lays groundwork for asking and testing a research question in the open-ended inquiry.

Options are offered for focusing inquiry on osmosis, transpiration, different cells structures, or combinations of these factors. The final discussion lets teams compare their bending achievements, share their findings, and come to a consensus of what factors cause stalk bending.

Grade levels

High school biology classes are the ideal target for this module. Students at this level have a basic understanding of biology, but complex concepts such as osmosis are still novel and tricky. The module can nevertheless be adapted for middle school and college classes. Many elaborations are appropriate for AP Biology, Botany electives, or undergraduate biology classes.

Class Time

The full investigation will take about two and a half weeks. The initial guided inquiries will take less than one week and can lead to an open inquiry extending at least another week. The concluding Storyboard Discussion requires two or three days, including team preparation time.

Celery Challenge Resources:

• Teacher's Guide
• Celery Challenge Toolkit
• Student's Guide
• Mentor Tip Sheet
• Related Links