What explains the result?
Light supplies energy for photosynthesis; height alone is not a full measure of plant health.
LIFE SCIENCE · GRADES 4–8
Seedling light investigation
INVESTIGATION QUESTIONHow does daily light condition change seedling growth?
● ILLUSTRATIVE SCIENCE MODEL
ENGLISH CAPTIONS
Match the seedlings. Matching conditions helps isolate the direction or amount of light.
0.0 / 3.0 s
Where does this matter?
Plant light needs guide greenhouse layouts, gardening, and crop production.
What should you keep in mind?
Keep water and seed conditions alike. The beginner model groups duration and brightness, so it cannot separate them.
DEDICATED PHOTOTROPISM INVESTIGATION · GRADES 5–10
Grow toward
the light
Control the direction of light entering a seedling chamber, advance one day at a time, and compare the stem bend with an angle guide.
LIGHT-EXCLUSION CARTON · TOP & SIDES COVEREDDAY 0/5
LIGHT BOX · ONLY THIS APERTURE
0°0°90°
☼SIDE LIGHT
ROOTS REMAIN IN MOIST SOIL
STARTDAY 1DAY 2DAY 3DAY 4DAY 5
ANGLE JOURNAL
Daily stem direction
Make a starting drawing and record an initial stem angle before exposing the seedlings.
WHY IT BENDS: Directional light triggers unequal growth on opposite sides of a shoot. This model shows a typical positive phototropic response; it does not predict the exact angle or speed for every species or growing condition.