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Cells and Systems 6-8 / Week 01 / Wednesday
3/6
Week 01 · Living or Not

Wednesday

Windowsill Lab: Plant the course seeds
// What every living thing does
⏱ about 20 min

Wednesday: Windowsill Lab: Plant the Course Seeds

Rocket has a jar in one hand and a fistful of dried beans in the other. "Plant them all! More beans, more science."

Raven lays a folded paper towel on the sill. "Three to five seeds. We need to see each one."

Nova hovers over the jar. "What does a resting seed need to wake up?" she asks.

"Water," Rocket says. "And light?" Raven shakes her head. "Not to start. Many seeds sprout underground, in the dark."

She dampens the towel and presses it against the inside of the glass. Rocket tucks a bean between towel and glass.

"Now we wait," Raven says. "And we measure." Nova's light glows. "This jar will be here for the whole course."

Your mission

Today you set up the course seed jar. Seeds planted today are measured for the next eleven weeks, so set it up with care.

A seed can stay inactive for a long time. When conditions turn favorable, such as moisture arriving, germination begins.

You will record what you see each day in the Windowsill Log. Nothing may happen for a few days. That is data too.

  • One clean glass jar or clear plastic cup
  • Two paper towels
  • Three to five dried beans or lentils, handed over by a grown-up from the pantry
  • Water in a cup, and a spoon for adding more
  • A ruler, a marker or tape for a label, and your Windowsill Log
Safety first
Use only dried beans or lentils a grown-up hands you from the pantry. Never use seeds from a garden packet.
Seeds are lab materials. Nothing is tasted, eaten or sniffed. Keep hands away from your face while you work.
The jar stays on the sill or table. A plastic cup works just as well if glass is a worry.
Wash your hands when you finish, and wipe up any spilled water.
  1. Fold a paper towel so it fits inside the jar and lines the glass all the way around.
  2. Dampen the towel with water. It should be wet all over but not dripping.
  3. Slide the damp towel into the jar and press it flat against the inside of the glass.
  4. Crumple the second paper towel and push it into the middle to hold the first towel against the glass.
  5. Tuck three to five seeds between the damp towel and the glass, spaced out, about halfway up the jar.
  6. Label the jar "Course seeds" with today's date. Set it on the sill out of direct, hot sun.
  7. Check the towel every day. Add a spoonful of water whenever it starts to dry.
  8. Record what each seed looks like today in your data table: size, color and whether it has changed.
PREDICT BEFORE YOU WAIT
  • Read the question.
  • Tap your answer.
Which part of a bean seedling do you expect to appear first?
The seeds are in the dark behind a towel. Will they still be able to start growing?
DaySeed 1Seed 2Seed 3Seed 4Seed 5Towel damp?
Wednesday
Thursday
Friday
Saturday
Sunday

What to watch for

A seed has a seed coat on the outside, and inside it holds the embryo and its food store.

The embryo has three parts you will meet as they appear. The radicle becomes the root. The hypocotyl becomes the stem. The plumule forms the leaves.

The radicle emerges first. Later the stem pushes up. The time a seedling takes to emerge varies with the kind and size of seed.

The seedling feeds on the food stored in the seed until its first leaves open and begin to make food from light.

Try it
Soak one extra bean in a cup of water for an hour while you set up the jar.
Look at the soaked bean beside a dry one with your hand lens. Which is bigger? Record it.
A SEED WAKES UP
  • Tap a card.
  • Then tap its spot.
1First
2Second
3Third
4Fourth
Draw your jar from the side. Show the towel, the seeds and the water line. Leave space to add roots later.

The jar is planted. Tomorrow you read a real table of what defines life, and test some tricky cases against it.

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