Designed By: Elizabeth Rogiani Temple University: College of Education
Objectives Students will be able to identify the structures in plants that are responsible for food production, and water transport. Students will be able to explain why flowers are able to change colors when food coloring is added to water.
Purpose/Goal The purpose of this lesson is for students to understand that plants need water to survive and grow. In order to achieve this, the students will see that the flowers suck up water through the roots to the stem and flower by conducting an experiment. In this experiment, the students will color water with food coloring. As the flower sucks up the water, the flower will begin to change to the color of the food coloring.
Information We know that plants need water to grow, make seeds, and stay healthy. But how can there be so many flowers that are unnatural colors? Here s how it works. The leaves and petals of plants have lots of small holes called stomatas. They're too small to see. Water evaporates through these holes. This is called transpiration. After the water evaporates, the plant needs more water to grow. If the flower is planted in soil, the roots of the plant get the water from the soil and then the water travels up through its stem. But, if the flower is in a container of water, it does not have any roots so it just sucks up the water through its stem. Let s see how this works!
Vocabulary and Concepts Carnation The carnation is a flower that is often used in bouquets and corsages. Evaporation The process of water molecules escaping the surface of the Earth and entering the atmosphere Stomata Tiny holes in the leaves that release water into the air Transpiration A continuous process caused by the evaporation of water from leaves of plants and its corresponding uptake from roots in the soil. Parts of a flower Flower Roots Leaf
Materials White Carnations Water Clear Glass Food Coloring Scissors
Data Chart Directions: For each Carnation, please record the time and any changes that may appear (Number of Carnations may vary) Time Carnation #1 (Blue) Carnation #2 (Purple) Carnation #3 (Red) Carnation #4 (Yellow)
Results Summary Carnation # Appearance in the Beginning Appearance after hours Note: Actual table should be all white for the students to draw their pictures.
Step 1: Make a Prediction What do you think will happen? Will the Carnation change color? Why or Why not? Write down your predictions on a piece of paper. How long do you think it will take to change color?
Step 2: Set up Experiment Have an adult cut the Carnation s stem. Fill clear glass with water about half way and place White Carnations in the glass.
Step 2: Set up Experiment Choose which food coloring colors you wish to use in this experiment.
Place 10-20 drops of food coloring into the glass of water. Step 3: Dye the Water Make sure the water is dark.
Check your Carnations every few hours to see how the petals change color. Step 4: Observe Record your findings in your data chart.
Experiment Results Carnations at beginning of experiment 12:15 PM Both flowers are completely white.
Experiment Results Carnations after about 1 hour and 45 minutes 1:45 PM The Carnation in the Blue water started to change slightly. The Carnation in the Purple water did not change.
Experiment Results Carnations after about another hour and a half 3:15 PM The rims of both of the flowers began to change to the color of the food coloring. The blue is more apparent.
Experiment Results Carnations after about another 2 hours 5:15 PM The purple is starting to become more apparent. The blue is very bright and spreading through the whole petal.
Experiment Results Carnations after about another 2 hours 7:15 PM The petals on the flower in the purple water is a very dull purple. The blue is very bright and the whole flower is almost all blue.
Reflection Take out your prediction paper and flip it over. Answer the following questions: Was your prediction correct? How long did it take your flowers to change color? Did anything surprise you? What did you learn? Did this experiment help you learn the concept? Would you recommend this experiment to a friend? Why or why not?
Conclusion As you probably noticed, most plants have a "drinking" problem. Okay, in this case it's a good problem. Most plants "drink" water from the ground through their roots. The water travels up the stem of the plant into the leaves and flowers where it makes food. When a flower is cut, it no longer has its roots, but the stem of the flower still "drinks" up the water and provides it to the leaves and flowers. Coloring the water with food coloring does not harm the plant in any way, but it allows you to see the movement of water through the roots to the shoots. Tiny tubes in the stem run all the way from the stem to the petals of the flowers. Our experiment indicates that the colored water traveled up the stem and into the petals of the Carnations.
Extension This popular trick is called "Split Ends" and it requires some help from an adult. Have your adult helper use a sharp knife to slit the stem straight down the middle. Make some predictions: Which color will be soaked up? Will the colors mix to make a new color? Put each half of the stem into a cup of different colored water (try positioning the red and blue cups next to each other, for example).
Links to Internet Resources Relating to Create a Graph: : http://nces.ed.gov/nceskid s/createagraph/ This Picture Lesson BrainPOP Video: http://www.brainpop.com /science/cellularlifeandg enetics/photosynthesis/ preview.weml
More Picture Lessons To see other picture lessons go to http://scienceinquiry.wikispaces.com/