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Grow It 3-5 / Week 05 / Wednesday
3/6
Week 05 · Leaves and Food from Light

Wednesday

Green machines
// How plants make their own food
⏱ about 15 min

Wednesday: Green Machines

Rocket wants to test light. "I'll put one bean in the window and one in the closet," he says.

Raven frowns. "What do you notice? One cup is big and one is tiny."

Nova hovers between the cups. "A fair test changes only one thing," she says. "What else must match?"

Rocket swaps in two cups that match. "Same cup, same soil, same water!"

Why leaves are green

Leaves are green because of chlorophyll.

Chlorophyll is a green pigment that captures light energy.

It is inside tiny parts of leaf cells called chloroplasts.

Photosynthesis happens in the chloroplasts.

Carbon dioxide gets into the leaf through the stomata.

INSIDE A LEAF
  • Read the question.
  • Tap your answer.
What makes leaves green?
Where does photosynthesis happen?
How does carbon dioxide get into a leaf?

Plan a fair test

Our question: does a bean plant grow better in bright light or in shade?

We change only one thing: the light.

Everything else stays the same.

Change thisKeep these the same
the amount of lightkind of plant, cup size, soil, water, room warmth
Is this a fair test?Fair?
Both plants get the same water. Only the light is different.?
The bright plant gets more water than the shade plant.?
One plant is in a big cup and one is in a tiny cup.?
Both plants are beans of about the same size.?
WHY THIS EXERCISEIf two things change, you cannot tell which one made the difference.
In a fair test, how many things do you change on purpose? Type the number.
WHY THIS EXERCISEChange one thing so you know what caused the result.
Try it: set up the test
Pick two bean seedlings that are about the same size, in matching cups.
Put one in a bright window. Label it Bright.
Put the other in a shady spot in the same room. Label it Shade.
Give both the same amount of water.
Measure both stems and write the numbers down.
Safety first
A grown-up helps move cups to high places.
Wear gloves for soil and wash your hands after.
Never eat seeds, leaves or any part of the plants.
For a grown-up
If you have only one seedling, start two more beans in matching cups today.
Shade means a dimmer spot, not a dark closet. Keep both plants in the same room.
DayBright stem (cm)Shade stem (cm)Leaf color notes
Wednesday
Thursday
Friday
Saturday
Draw your two test cups. Label Bright and Shade. List what stays the same.

Fantastic fair testing! Tomorrow we follow the Sun's energy all the way to you.

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