Chlorophyll just beneath the surface of a leaf stores energy from the sun that is used to make glucose, which plants use as food. The chlorophyll is what makes plant leaves green. Help your students find out what happens when sunlight can’t reach the leaves of a plant. Have them take a picture of a healthy indoor plant and completely cover one leaf with black construction paper and tape. They should water the plant as needed. After a week, tell them to remove the construction paper, take an “after” picture, examine the leaf and record the results.
Each student needs three clear containers with lids, two boxes larger than the containers, radish seeds and paper towels. Have students paint the insides of both boxes black, make five holes in the wall of one box and cover the holes with tracing paper. Tell them to layer paper towels in the bottom of each container, add the same amount of water to each, place 50 radish seeds on the paper towels and put on the lids. They should put one container in the lightproof box, one in the box with holes and the third where it gets indirect sunlight. When the seeds in the third container have roots and several leaves, tell students to count the germinated seeds, measure the root and stem lengths and note any differences among the germinated seeds in the different containers.
Have each student sprout a bean seed in a small plastic cup. When the bean sprout has a set of leaves, have students cut a 2-inch by 3-inch rectangular opening in one end of a large shoebox. Each child should cut two pieces of extra cardboard the height of the shoebox by half the width. Tell them to tape the cardboard pieces inside the box, perpendicular to the sides, at positions 1/3 the length and at 2/3 the length of the box, to make a simple maze. They should turn the box on end with the opening on top, put the well-watered plant in the bottom of the box, tape the lid on and put in a sunny area. Have the class check their plants in five days. Have students allow the plants to grow longer, if needed.
Help your students plant bean seeds in six identical containers. After the plants have true leaves, have students weed out all but the healthiest in each container, place one plant on a sunny windowsill and place another in a large box with a plant (full-spectrum) light above it. Then have students construct four boxes with one side and the top made of colored plastic wrap or cellophane -- one each of red, blue, yellow and green. Tell students to place a plant in each box and place the boxes on a sunny windowsill. Have students water each plant the same amount, record observations each day and take pictures of the plants’ progress. After two weeks, have students compile results to see how the color of light affects plant growth.