Seed Lab: Which Way Is Up?
Students plant a bean upside down in a dark closet. Its first root comes out going up, curves around and grows down. On Day 11 it comes up anyway, pale and hooked: seeds do not need light to sprout. They move it to a sunny window, where it opens green leaves and leans toward the light. Then they turn the pot, and lay it on its side: within a day the top curves up again, and the roots turn down.
At a glance
Essential question
How does a plant know which way is up?
Objectives
Students will be able to:
- observe that a root grows down and a shoot grows up, whichever way the seed lies
- show that a seed sprouts in the dark but a seedling needs light to turn green
- describe how a stem bends toward light and away from gravity
- explain how these responses help a plant survive
Vocabulary
Gravity, Respond, Shoot, Root, Sprout
Standards
4-LS1-1, SC.3.L.14.2
Time and materials
45 minutes, grades 3-5.
- One computer or Chromebook per student
- A projector
- The worksheet and exit ticket, one copy each per student
- The rubric, one copy per student if you grade the work
Prep
Make copies of the worksheet and exit ticket. Before class, open mytekdev.com/try/seedlab?lesson=which-way-is-up&ref=tpt-seedlab-3 once on a student computer: a bean is planted upside down in a closet. Run it yourself, about ten minutes: Next stage to the first root (it comes out going up, then curves down), Next stage to up (Day 11, pale and hooked), South window, run to about Day 20, then Lay it on its side and run one more day.
Assessment
- Formative: the questions under What to look for, asked while students work, and the exit ticket (answer key included).
- Summative: the worksheet, scored with the rubric.
Technology and privacy
Runs in any browser, Chromebooks included, with nothing to install. Students need no account and no email: the link works signed out, and nothing they do is stored on our server unless they choose to save.
mytekdev.com/try/seedlab?lesson=which-way-is-up&ref=tpt-seedlab-3mytekdev.com/tools/seed-lab/lessons/which-way-is-up/startEach student gets their own copy, and the same link reopens it next time. How to set up a classLesson sequence
| Minutes | Stage | What you do | What students do |
|---|---|---|---|
| 0 to 5 | Warm-up Hook | Show the title, essential question and Today I can slides (about 1 minute). Then the warm-up: plant a seed upside down, which way does its root grow? | Answer the warm-up on the worksheet. |
| 5 to 12 | Direct instruction (I do) Model it | Project the app with the starter open. Point out that the bean is upside down and the closet is dark. Press Next stage until the first root shows (Day 4): it comes out going up and starts to curve. Show the upside-down slide. It's working when: Roots sense gravity with tiny grains in their tips. In the dark there is no light to follow, and the root still finds down. | Watch, and fill in the vocabulary on the worksheet. |
| 12 to 22 | Guided practice (We do) Up in the dark | Students open the link or scan the QR code. A short guide takes them to up (Day 11) in the dark, then to the window. Ask: did the seed need light to sprout? Watch for: Students who say seeds need light. The closet seedling came up anyway; it is pale because it has not had light yet. | Draw the plant in the dark and after a few days in the light. |
| 22 to 38 | Independent practice (You do) Tip it over | Students run to about Day 20, lay the pot on its side, run a day, stand it up, then turn the pot so the leaves face the room. Walk the room with the What to look for questions. If they ask: "You turned the pot. Which way does the new growth bend over the next few days, and why?" Turned around | Draw each change in the drawing table. |
| 38 to 45 | Closure Showcase and exit ticket | Show the Showcase slide. Two students explain how growing down and growing up help a plant, then go back to the warm-up answers. Hand out the exit ticket. | Answer the exit ticket. |
Before you teach: a ten-minute walkthrough
Open mytekdev.com/try/seedlab?lesson=which-way-is-up&ref=tpt-seedlab-3. A short guide opens over the app. A bean is planted upside down, 2.5 cm deep, in a closet: the stage is dark.
- The root. Press Next stage: the first root comes out on Day 4 going up, and curves around to grow down.
- Up in the dark. Keep pressing: the shoot comes up on Day 11, pale yellow with its hook still bent. The guide asks for light.
- Light. Pick South window and run to about Day 20: the seed leaves open green, the first leaves open, and the stem leans toward the window.
- Tipped over. Press Lay it on its side and run one day: the top curves up. Stand it up: the bend stays. Then Turn the pot: over a few days the new growth bends back toward the window.
Background for the teacher
Roots grow toward gravity and shoots away from it, sensed by tiny grains in the root tip and the stem. Shoots also bend toward light: the shaded side grows more, so the stem leans to the bright side. Only the young growing part near each tip bends; older stem stays where it grew.
A seed needs water, warmth and air to sprout, not light. In the dark, a bean seedling grows tall and pale on the food stored in its seed, with its hook still bent, and dies when that food runs out (about Day 19). Given light, it opens green leaves and makes its own food.
Common mistakes: seeds need light to sprout; a root grows whichever way the seed points; plants cannot move. The app grows one model plant, the same way every time, so two students with the same settings get the same numbers. Real plants vary from seed to seed; a real bean in a bag beside the app shows that.
What to look for
Ask these while students work. A student who has understood the lesson can answer them without help:
- Which way did the root first come out, and which way did it end up?
- Did the seed need light to sprout? How do you know?
- Why was the seedling pale in the closet?
- What happened to the top when you laid the pot on its side?
- How does growing down help a root? Growing up help a shoot?
Cross-curricular extensions
- Real plants: tape bean seeds to a damp paper towel in a clear CD case, stand it up, and turn it a quarter turn after the roots show.
- Art: draw the upside-down seed's root as a comic strip, one frame a day.
- English: explain to a younger student how a plant knows which way is up.
- Math: how many hours did it take the top to turn up after the pot was laid down?
Vocabulary
| Gravity | The pull that makes things fall down. |
| Respond | To change because of something around you. |
| Shoot | The part of a young plant that grows up out of the soil. |
| Root | The part of a plant that grows down into the soil and takes in water. |
| Sprout | When a seed starts to grow: the root comes out first. |
Differentiation
English learners
- Keep the vocabulary slide up, and point at the screen as you say each word: the jars, the roots and the stage chips carry the meaning.
- Pair each learner with a partner; up and down show on the screen without words.
- Accept the drawing table as drawings with arrows.
Students with IEPs or 504 plans
- Pair students for the independent part, one at the app and one drawing.
- Zoom the browser to 125%.
- Allow two drawings instead of four, where the IEP allows a modified assignment.
Students who need more support
- A sentence starter: "The root grows ___ because ___."
- A check-in when the plant is up: every student has moved it to the window before anyone tips it.
- Ask only: which way did the root go?
Students ready for more
- Leave a second bean in the closet. What happens to it by Day 19, and why? (Read the card.)
- Try a pea, which leaves its seed below the soil. How is its seedling different?
- Grow a sunflower outdoors and pause on Day 40 in the morning and the evening. Which way does its bud lean?
Adapting for other grades
Younger students: In grades 1 and 2, do it together on the projector: plant upside down, press Next stage, and ask which way the root went. Skip the turning and the drawing table.
Older students: In middle school, name the responses (gravitropism and phototropism) and explain them with growth on one side of the stem (MS-LS1-5: an environmental factor changes how a plant grows).
Seed Lab: Which Way Is Up?
Student worksheet
Name: ______________________________ Date: ______________
Open the app: scan the QR code, or go to mytekdev.com/try/seedlab?lesson=which-way-is-up
Essential question: How does a plant know which way is up?
Warm-up: If you plant a seed upside down, which way will its root grow? ________________________
- Vocabulary. Gravity, respond, shoot, root, sprout: write each in your own words.
- The drawing table. Draw the plant: upside down when the root first shows; up in the dark; after a few days in the light; laid on its side for a day. Add an arrow for which way it grew.
1. Did the seed need light to sprout? What is your evidence?
2. How do roots growing down and shoots growing up help a plant survive?
Seed Lab: Which Way Is Up?
Exit ticket
Name: ______________________________
1. A bean seed is planted upside down. Its root will grow (A) up, the way it points (B) down, toward gravity (C) sideways
2. A seed in a dark closet (A) never sprouts (B) sprouts and comes up pale (C) comes up green
3. A potted plant is laid on its side. Describe what its top does over the next day, and why.
Answer key: exit ticket
| Question | Answer | Why |
|---|---|---|
| 1 | B | The root turns down whichever way it starts, following gravity. |
| 2 | B | Seeds do not need light to sprout. The seedling is pale because it has no light yet. |
| 3 | It curves up | The growing tip bends away from gravity, so the top turns up. "It moves" alone is half. |
Rubric
Score each row from 1 to 4.
Name: ______________________________
| Criteria | 4 Exceeds | 3 Meets | 2 Approaching | 1 Beginning |
|---|---|---|---|---|
| The drawings | Upside-down seed, up in the dark, in the light, and laid down, each with arrows for which way it grew. | Three of the four, with arrows. | Some drawings, no arrows. | No drawings. |
| Light and gravity | Says the root follows gravity, the shoot grows away from it and toward light, and gives evidence from the app for each. | Says the root grows down and the shoot up, with one piece of evidence. | Says the root grows down, no evidence. | No answer. |
| Why it matters | Explains how each response helps: roots reach water, shoots reach light. | Explains one of the two. | Says it helps the plant, with no reason. | No answer. |
Total: ____ / 12. A score of 9 or more meets the objectives.
Standards
The lesson is built for 4-LS1-1, structures that support survival and growth, and for Florida SC.3.L.14.2, which names stems growing toward light and roots growing down with gravity.
| Framework | Code | Grades | Standard | How the lesson meets it |
|---|---|---|---|---|
| NGSS | 4-LS1-1 | 4 | Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction. | Students connect roots growing down and shoots growing up to how each part helps the plant survive. |
| Florida | SC.3.L.14.2 | 3 | Investigate and describe how plants respond to stimuli (heat, light, gravity), such as the way plant stems grow toward light and their roots grow downward in response to gravity. | Students watch the stem grow toward light and the roots grow down, and test both by turning and tipping the pot. |
Checked November 2026 against: NGSS 4-LS1-1, From Molecules to Organisms, Florida SC.3.L.14.2 (CPALMS).
Optional: save student work in a free class
The whole lesson runs at the link on the worksheet, with no accounts and no sign-up.
To keep students' work, and see it all in one place, make a free class. It takes about ten minutes, once, and covers every lesson in this series: mytekdev.com/tools/class-setup
Students in a class open mytekdev.com/tools/seed-lab/lessons/which-way-is-up/start instead of the worksheet link. Each one gets their own copy of the starter, and the same link reopens it next time.