What happens to a leaf when part of it stops getting sunlight? You cut shapes from cardboard or aluminum foil and clip them onto leaves of a living plant. The shapes block sunlight from reaching that section of the leaf.
After four days you remove the shapes. The covered areas look different from the rest of the leaf. Without sunlight, the plant cannot run photosynthesis (the process that makes food and keeps leaves green) in those spots.
Hypothesis
The hypothesis is that without enough sunlight, plants cannot use the process of photosynthesis to produce food.
Without sunlight, photosynthesis cannot run — and leaves show it. You clip cardboard shapes onto leaves of a living plant, blocking sunlight from reaching those sections. After four days, the covered spots look different from the rest of the leaf.
Plants soak up light to make their own food. When you clip cardboard or aluminum foil shapes onto a leaf, those covered areas stop getting sunlight. As a result, the plant cannot run photosynthesis in those spots — the process that makes food and keeps leaves green. After four days, you can see the difference: the blocked sections look noticeably different from the rest of the leaf.
Chlorophyll is the green pigment that captures sunlight to make food for plants — but it needs light to do that job. When you clip cardboard shapes onto leaves of a living plant, those shapes block sunlight from reaching that section of the leaf. After four days, remove the shapes and compare the covered areas to the rest of the leaf. Without sunlight, photosynthesis cannot run in those spots, and the green fades.
Method & Materials
You will pick a shrub, tree or houseplant, cut out some geometrical shapes, paperclip each shape on a different leaf, and observe the effects after four days.
You will need a small shrub, tree or house plant, cardboard or aluminum foil, scissors, and paper clips.
The results of this experiment show that without enough sunlight, plants cannot use the process of photosynthesis to produce food. The leaves that were covered with shapes showed a lack of growth compared to the other parts of the leaf.
Why do this project?
This science project is interesting because it shows how plants need sunlight to survive and how a lack of sunlight can affect their growth.
Also Consider
Experiment variations to consider include changing the shapes used to cover the leaves, changing the amount of time the shapes are left on the leaves, and using different types of plants.
Full project details
Additional information and source material for this project are available below.
