How Does a Glucose Solution Affect the Longevity of Cut Flowers?
Project Idea by: Connor Janeski
Plants produce their own food, mainly in their leaves, by a process called photosynthesis. This food-making process uses light, a form of radiant energy, to change carbon dioxide gas and water into oxygen and glucose (a type of sugar needed by plants and animals). Plants can change the sugar into energy, which can be used for all plant processes necessary for life and growth.
Plants have tube-shaped structures called xylem that carry sap from the roots to other parts of the plant. Sap is a liquid solution (a mixture of a liquid with substances dissolved in it) containing nutrients including glucose. When the stem connected to a flower is cut, sap can continue to move through the xylem if the cut end is placed in a liquid. The longevity (the length of life) of a cut flower depends on several things, one being the continued movement of sap to the flower. Without sap, cut flowers will wilt (become limp or droopy). Since plants need glucose to make energy, a project question might be, "What effect does a glucose solution have on the longevity of cut flowers?"
Clues for Your Investigation
Often, a cut flower quickly dies because microbes (organisms that are too small to be seen with the unaided eye) multiply and form a plug in the end of the cut stems, blocking sap from moving through the xylem. To increase the longevity of cut flowers, it is important to use clean cutting tools and containers, which helps control the growth of stem-plugging microbes. Cutting the stems while holding them under water prevents air bubbles from plugging the stems. Use the same kind of flowers and the same cutting tools and procedure to collect or to prepare purchased flowers.
A source of glucose is white corn syrup. Decide on the amount of syrup that will be used for each test and mix it with distilled water. Put several flowers in a vase or jar containing a different amount of glucose and one with no glucose (the control). Design a method of measuring the longevity of a cut flower. For example, the flower will be considered dead when any part of its petals change color.
Independent Variable: Amount of glucose
Dependent Variable: Longevity of cut flowers
Controlled Variables: Type of flower, how the flower is cut, cutting tools, containers, distilled water, environmental conditions
Control: Distilled water—no glucose
Other Questions to Explore
How would these variables affect the longevity of cut flowers: (1) Water temperature, (2) tap water instead of distilled water, and (3) table sugar instead of corn syrup?
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