Transformations in Matter and Energy Carbon TIME is an NSF-funded partnership led by Michigan State University
Activity 3.3: Observing Plants in the Light and Dark (60 min over 2 days)
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
- 3.3 Observing Plants in the Light and Dark Worksheet (1 per student)
- 3.3 Grading the Observing Plants in the Light and Dark Worksheet
- 3.3 Observing Plants in the Light and Dark PPT
- 3.3 Plants in the Light and Dark Class Results 11 x 17 Poster
- Optional 3.5 Evidence-Based Arguments Tool for Plants
- Carbon TIME Growing Plants Video
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.
- Refer to the BTB Information and Instructions Handout for information about preparing BTB.
- Prepare your computer and projector for the 3.3 Observing Plants in the Light and Dark PPT.
- Print one copy per student of the 3.3 Observing Plants in the Light and Dark Worksheet.
- Print one copy of the 3.3 Plants in the Light and Dark Class Results 11 x 17 Poster.
- Use the class discussion to interpret how successful your students are at identifying patterns in the class data. Use the 3.3 Grading the Observing Plants in the Light and Dark Worksheet to determine if your students had any trouble with data collection.
- During this activity, note students’ success in observing changes in BTB. Also note students’ ability to reach a consensus about patterns in data and how they interpret results.
- The discussion in step 5 can be helpful for informal assessment in two ways: 1) it can help you assess your students’ skills in identifying sources of error and finding patterns in data, and 2) it can help you assess how well students identify the limits of the evidence. Do they recognize that the investigation does not fully answer the Three Questions?
- Discuss threats to accuracy of measurement.
- Check to see if students can identify unanswered questions from the investigation.