Teaching with Seed Lab
For science teachers, co-op leaders and parents. One period on where a plant's mass comes from, one on what a plant needs and how it responds, what students get wrong and where the app answers it, and the sheet and the setup.
Using this with a class? Make a free class and add your students yourself: each gets a username and password, with no email or Google account needed. Or give them one join code. Using Google Classroom? Post the link there; with a free class, the link also puts each student in your class, so you see their work. mytekDev is also available from the Google Workspace Marketplace, so your school's Google admin can install it for everyone.A first lesson: One period: guess where the plant's weight will come from, plant a bean and watch the root come first, open the ledger once it is up, then run it outdoors to ripe seeds and compare the jars with the guess. Weigh the soil before and after.
Set up a free class Share to Google Classroom- About these notes
- Period one: where does a plant come from?
- Period two: what a plant needs, and how it responds
- What students get wrong, and where the app answers it
- What the app simplifies, on purpose
- Grades 3 to 5, middle school and high school
- The sheet and the setup
- Standards
About these notes
Seed Lab is one plant in a pot with a glass front, stepped an hour at a time. Students choose a bush bean, a pea, a dwarf sunflower or a radish, a pot size and a soil, plant the seed by dragging it into the soil, and run the days. The roots show through the glass. The ledger beside the pot keeps the books on the plant's dry mass in four jars: from the seed, from the air, from the water, from the soil. Water that goes in at the roots and out at the leaves is counted on its own line.
How fast a seed comes up at each soil temperature is read from published germination tables. After that, growth runs on degree days, light caught by the leaves turned into sugar, respiration burning some of it day and night, and a water bucket in the pot. The same setup gives the same plant every time, which makes fair tests easy and is not how real plants behave: say so.
Period one: where does a plant come from?
- The guess (5 minutes) Everyone opens the app and drags the bean into the soil. Before Start, the app asks where the plant's weight will come from: soil, water, air, sunlight. Students tap all they think. Take a quick count of the class.
- The root comes first (10 minutes) Press Start and Next stage. The seed swells, the first root comes out on about Day 4 and turns down. On Day 11 a pale hook comes up through the soil. Open the ledger: the plant is about 0.24 g, less than the 0.28 g seed. It has been burning the seed's food.
- Outdoors to seed (15 minutes) Start over, choose Outdoors, tick the water helper and set a day a second. The bean flowers about Day 40 and ripens on Day 85 with 14 seeds. The ledger: 14.5 g of dry plant, 12.8 g from the air, 0.85 g from the water, 0.71 g from the soil, and about 8.8 liters of water through it.
- Weigh the soil, and talk (15 minutes) Press Weigh the soil: it lost 0.71 g, exactly what the soil jar holds. Compare with the class's guesses. Tell van Helmont's story: a willow grown five years in 200 pounds of dried soil gained about 164 pounds while the soil lost about 2 ounces.
Period two: what a plant needs, and how it responds
Put a bean in the closet: it sprouts on the same day as one in the window, then grows tall, pale and hooked and dies of the dark around Day 19. Seeds need water, warmth and air to sprout; light matters once there are leaves. Plant a seed upside down: the root comes out going up and curves down. Grow one, then lay the pot on its side: within a day the young top turns up, and the bend stays when it stands again. Turn the pot: the new growth bends back toward the window.
Then one change at a time. Start over keeps nothing; the Back in time slider returns to any earlier day so a student can make a different choice from there and grow the days after it again. At 21 degrees in a medium pot on the south window a bush bean ends at about 3 g with 3 seeds; under the grow light that is always on, about 8 g with 8 seeds; outdoors, 14.5 g with 14. A small pot holds it back; sand runs out of minerals and dries before a seed sprouts; clay watered twice a day drowns it sooner; nights over about 22 degrees cost a bean its flowers.
What students get wrong, and where the app answers it
| What students say | Where the app answers it |
|---|---|
| The plant's weight comes from the soil | The jars and the scale: the soil jar holds a few grams in every hundred, and the dried soil lost exactly that. |
| It comes from the water | The water line: liters went in at the roots and out at the leaves, and only grams stayed. The air jar is about fifteen times the water jar. |
| A gas can't weigh that much | The air jar in grams: 12.8 g of an outdoor bean was carbon dioxide from the air. |
| Plants eat sunlight | Light is on the window, not in a jar: it is the energy the plant uses to make sugar, not something it is made of. |
| Fertilizer is plant food | The fertilizer button says minerals, not food, and far too much of it burns a seedling's roots. |
| Seeds need light to sprout | The closet: the seed sprouts on the same day as in the window. |
| Plants only breathe in carbon dioxide | Used up for energy, and the dry mass that dips every night. |
| Roots grow down because they are planted that way | An upside-down seed, and a pot laid on its side. |
What the app simplifies, on purpose
- Every run is the same. Real plants vary, and seeds from one plant differ only a little in size here.
- The ledger counts by where the atoms go: carbon and the plant's oxygen from carbon dioxide, hydrogen from water, about 4 grams in every 100 from the soil. The high school level shows a second honest count, by what goes in and out, where the water side looks bigger. Real young plants can carry up to about 8 grams in every 100 from the soil.
- Some numbers are our own estimates and are being checked: how much leaf a gram makes, how fast roots grow, the share of food burned for energy, how a pot or a soil holds water, how heat costs flowers, and the dwarf sunflower's size indoors.
- Pests, mold, wind and humidity are left out. Outdoors, bees pollinate without being drawn. One radish alone sets almost no seed, and the app does not yet grow two side by side.
- A windowsill is dim, so plants there stay small. That is true, and worth saying before students are disappointed.
Grades 3 to 5, middle school and high school
| Level | What changes |
|---|---|
| Grades 3 to 5 | The jars show no numbers, and the card has no grams. The words stay plain. |
| Middle school | The jars, the card and the journal in grams, the water through the plant in milliliters and liters. |
| High school | Degree days and light in mol a day on the card, and the books counted a second way, with a card explaining both. |
The sheet and the setup
The Sheet asks four questions: what the plant needed to sprout and to grow, where most of its mass came from, what happened to the water it took in, and what to change next time. It shows the guess and the ledger, waits for every answer before Hand it in, and prints with a picture of the plant.
Setup, opened from the Sheet: which seeds and lights students can choose, whether a day in 1 second is allowed, a guess before Start, weekend cooling for new pots, and the puzzles. Its answer key is worked out from the model: for each seed, the day it comes up at 18, 21 and 25 degrees, first flower, ripe, seeds on the window and under the always-on grow light, and the deepest it comes up from.
Standards
NGSS performance expectations, with the boundaries the app keeps.
- 5-LS1-1: plants get the materials they need for growth chiefly from air and water. The ledger is this expectation.
- 3-LS1-1: the life cycle of a flowering plant, seed to seed.
- 4-LS1-1: roots, stems, leaves and flowers, kept to what can be seen.
- MS-LS1-5: light, water, warmth and the pot changing growth, with no genetic mechanism.
- MS-LS1-6: photosynthesis as matter moving in and out, with no biochemistry.
- MS-LS1-4: flowers, pollination and seeds.
- HS-LS1-5 and HS-LS2-5: the sugar equation's masses and respiration, in grams.
- Florida SC.3.L.14.2: stems grow toward light and roots down with gravity.
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Page last reviewed November 2026.
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