Plants Activity 3.3 Overview

Target Student Performance

Students observe how plants affect BTB in the light and dark, identify patterns in data, and reach consensus with other groups about their results.

Resources You Provide

  • Radish plants (either in tubes (GL) or containers (PT) from the Pre-Lesson. Note: 3-4 tubes or 1-2 containers will be plenty for each experiment replicate.
  • Dark box, thick black trash bag, or very dark closet (1 per class)
  • Fluorescent grow light or sunny windowsill (1 per class)
  • Label (1 per group student group)
  • Petri dish with blue BTB (1 per container/student group)
  • Petri dish with yellow BTB (1 per container/student group)
  • Sealable 6.8 liter (or 29 cup) container (1 per group)
  • (From previous lesson) 3.1 Predictions and Planning Tool for Plant Investigations with student answers

Resources Provided

Recurring Resources


Assign each group of students a treatment (light or dark). For each group, select growing radishes (3-4 GL tubes or 1-2 PT containers) that were planted in the Plants Unit Pre-Lesson. For each group, provide 1 sealable 6.8-liter (29 cup) container, one Petri dish of blue BTB, one Petri dish of yellow BTB, and a label. Prepare enough space under a grow light or in a sunny windowsill for the “plants in the light” containers, and enough room in a dark closet for the “plants in the dark” containers. Optionally, print a few copies of the BTB Color Handout for students to use as a color reference.