Color-Changing Cells

Leaves are just doing what comes naturally when they change colors and fall from trees. Find out more about this process and display your knowledge in naturally colorful way.

• 1.

  Autumn is a time for the beauty of the turning leaves. What causes that transformation? As the length of days and nights change (photoperiodism) and the amount of available daylight decreases, a plant’s ability to produce chlorophyll (photosynthetic pigment) is reduced. Senescence, the process of aging and death of plant part (leaf) begins to occur. Nutrients return to the stems and roots of the plant, abandoning the leaves. When the green chlorophyll is gone, yellow and orange carotinoids that have been always present are left.

• 2.

  Learn more about cells that form where the leaf and stem connect. After you understand the chemical processes, decide how to depict your knowledge in a three-dimensional exhibit. Here’s one way to show it.

• 3.

  Draw a leaf on cardboard with Crayola® Gel Markers.

• 4.

  Form leaf cells with Crayola Model Magic. To create your own colors, cover white Model Magic with the marker color. Knead to blend in the color. Air-dry your leaf cells.

• 5.

  Use Crayola School Glue to hold cells in their proper places on the cardboard drawing. Air-dry the construction.

• 6.

  Label a key with matching colors and explanations of the color-change process. Add borders or other enhancements to your project before presenting the information to other students.

Benefits

• Students gather information about photoperiodism and senescence.
• Students visually represent their understanding about these processes in a 3-dimensional model.
• Students graphically distinguish between colors in a key.

Adaptations

• Look up any technical terms. Rephrase definitions and add the words to your spelling list. 
• Learn more about the effects that chemicals such as anthocyanin and tannin have on different species of plant leaves. Create accompanying models of these findings.
• Mask parts of leaves on a tree as senescence begins. Graph the effect of sunlight on the process. Find out what happens at the stem site where the leaf falls off.
• Assessment: Ask students to check each other’s models for accuracy and clarity of presentation.