Do plants bend toward the window?
- 👶 Small parts
- 🧼 Wash your hands after
My hypothesis
If I change where the light comes from, then how far the top of the plant leans from straight up will ______, because ______.
You fill in the blanks. Think about what a plant uses light for, and where it would want its leaves. A guess is a good because: the test finds out.
Change, measure, keep the same
CHANGE
where the light comes from: Windowsill, never turned, Windowsill, turned every day, Box with a hole on one side
MEASURE
how far the top of the plant leans from straight up, in cm
KEEP THE SAME
- the same kind of bean, planted the same day
- the same water each day
- the same room
Scientists call the thing you change the independent variable and the thing you measure the dependent variable. The things you keep the same are the controls: if one of them changed too, you wouldn't know which change made the difference. Try each of the 3 levels 3 times.
What you need
- Dried beans from the grocery bag (pinto, lima or kidney): 9
- Paper cups with a hole poked in the bottom: 9
- Potting soil
- Water from the tap
- A shoebox: a shoebox with a lid
- ✂️ Kid scissors
- 📏 A ruler
Steps
- Plant one bean in each of nine cups of soil, a finger deep, and water them.
- Water them a little each day until they're about 5 cm tall. That takes about five days.
- Grown-up: A grown-up cuts a coin-sized hole in one end of the shoebox.
- Put three cups on a sunny windowsill and never turn them.
- Put three more beside them, and turn each one halfway round every day.
- Put the last three in the box with the hole toward the window, and close the lid.
- Each day, hold a ruler straight up beside each stem and measure how far the top leans.
- After seven days, find the middle lean for each spot and draw a bar graph.
- Wash your hands after touching the soil.
One step is a grown-up's, marked above. Write each number down straight away, in the table below, so nothing is lost.
Your results table
Name ______________________ Fair day ____________
Question: Do plants bend toward the window?
I changed: Where it grows I measured: how far the top of the plant leans from straight up (cm)
| Where it grows | Try 1 (cm) | Try 2 (cm) | Try 3 (cm) | Mean |
|---|---|---|---|---|
| Windowsill, never turned | ||||
| Windowsill, turned every day | ||||
| Box with a hole on one side |
MY GRAPH (a bar graph: where it grows along the bottom, cm up the side)
What I noticed: ______________________________________________
From 4th grade, add the tries for each level and divide by how many there were: that's the mean, and it goes in the last column. Then draw a bar graph, one bar for each thing you tried.
Name ______________________ Fair day ____________
Question: Do plants bend toward the window?
If I change where the light comes from, then how far the top of the plant leans from straight up will ________________, because _____________________________________________
| I CHANGE | I MEASURE | I KEEP THE SAME |
|---|---|---|
| Where it grows: Windowsill, never turned, Windowsill, turned every day, Box with a hole on one side | how far the top of the plant leans from straight up (cm) |
|
What I think will happen, in my own words:
Name ______________________ Fair day ____________
Question: Do plants bend toward the window?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Do plants bend toward the window?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Do plants bend toward the window?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Do plants bend toward the window?
My hypothesis was ☐ right ☐ partly right ☐ not right.
I know because my numbers show:
What surprised me, or what might have gone wrong (7th and up):
Next time I would test:
Idea: Change a second thing: cover the box's hole with red, blue or green see-through plastic, and find which colour the plants bend toward most.
Why it works
Plants grow toward light because light is how they make their food. A growth substance gathers on the shady side of the stem and makes those cells grow longer, which bends the top toward the light. Turn the plant every day and the bend keeps getting undone, so it grows straighter.
Going further (7th and up): Change a second thing: cover the box's hole with red, blue or green see-through plastic, and find which colour the plants bend toward most.
Board layout
- ❓ Question (10 × 8 in): Do plants bend toward the window?
- 💭 Hypothesis (10 × 9 in): If I change where the light comes from, then how far the top of the plant leans from straight up will ______, because ______.
- 🧺 Materials (10 × 12 in): 5 things: see your list.
- 🪜 Steps (22 × 9 in): 9 steps, three tries at each level.
- 📊 Results (22 × 16 in): Your table (Where it grows down the side, tries across) and your bar graph.
- ✅ Conclusion (10 × 14 in): My hypothesis was right / partly right / not right. I know because…
Materials to list: Dried beans from the grocery bag (pinto, lima or kidney); Paper cups with a hole poked in the bottom; Potting soil; Water from the tap; A shoebox.
Bring photos or drawings of your test. Nothing wet, hot, powered or alive on the table.
This project at your grade
| 1st–3rd grade | Tries: three at each level (one is fine at a first fair). The table: levels and tries, numbers or pictures. The graph: a picture, or a simple bar graph. The conclusion: what happened, in their words. |
|---|---|
| 4th–6th grade | Tries: three at each level. The table: units in the header and a mean column. The graph: a bar graph, or a line for a number that grows. The conclusion: right, partly or not, and the numbers that show it. |
From 4th grade up, the table gets a mean column. See every project for 1st grade, or print a blank results table.
What a judge will ask
- What did you change, and what did you measure? I changed where the light comes from and measured how far the top of the plant leans from straight up, in cm.
- What did you keep the same, and why does that matter? I kept the same kind of bean, planted the same day and the same water each day the same, so the only difference was where the light comes from.
- How many times did you test it? 3 times at each of my 3 levels.
- If you did it again, what would you change or test next? I'd cover the box's hole with red, blue or green see-through plastic, and find which colour the plants bend toward most.
Make it yours
Keep this project on this device and Peabody counts down to your fair day, with a plan for each day. Nothing is sent anywhere.
Try next
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