Seed Lab lesson plans
Each one is a class period with everything to run it: a teacher plan, a student worksheet, an exit ticket with answers, and the standards it meets. Students need no account, and a free class saves their work.
Seed Lab: Where Does a Plant Come From?
Students guess where a growing plant's weight comes from: soil, water, air or sunlight. Then they grow a bush bean outdoors and read the ledger, four jars that keep the books on its dry mass. By Day 60 the plant is 12 g dry: 11 g came from carbon dioxide in the air, 0.70 g from water, 0.54 g from the soil. They weigh the dried soil, which lost only about half a gram, and meet van Helmont, who grew a willow in a pot for five years.
FreeSeed Lab: Seed to Seed
Students grow a bush bean from seed to seed. The stage chips light up one by one: the seed swells, the first root comes out on Day 4, the shoot comes up on Day 11, leaves open, flower buds on Day 35, flowers on Day 40, pods on Day 46, and on Day 85 the seeds are ripe. They count the seeds (14, outdoors) and plant one of them: generation 2 starts the same cycle again.
FreeSeed 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.
FreeSeed Lab: One Change at a Time
Students grow the same bush bean to its first flowers (Day 40) and record its dry mass. Then they go back in time to the start, change one thing, and grow it again. On Day 40 the light alone takes it from 0.24 g on a north window to 0.91 g on a south window, 2.7 g under a grow light that is always on and 7.6 g outdoors. Pot size and warmth each tell their own story. They graph the results and explain them as environmental factors.