Celery Microclimate Experiment

Introduction:
Plants and animals respond to the climate that surrounds them. People can adjust to the climate by choosing clothing to keep us at a comfortable temperature. Plants respond differently to the climate where they are growing. In this experiment we will observe how temperature can effect the rate of liquid uptake in the celery plant.

Materials:
4 thermometers
4 jars
4 freshly cut celery stalks
potato peeler
red food coloring
cool water

Methods:
1. Locate testing sites: Where are the coldest and the warmest places at your home/school? Brainstorm a list of places you could test the temperatures. Find 4 locations if you can.
Test your ideas by placing a thermometer in each location and check the temperatures a few times during the day. Experiment until you have the biggest difference between cold and warm with variations in between.
2. Explain to the class that they will be carrying out an experiment with celery and colored water. They will be putting the celery in 4 places, each with a different temperature. Ask them to predict how long it will take for the food color to be drawn up the stalks. Which location will it happen the fastest, and which one will be slowest?
3. Create a chart to record your uptake measurements. Across the top of the chart, head columns with the numbered site and the temperature you recorded at each site. Label the rows, "Height of blue column at time intervals." Your time intervals should be about every 5 minutes. Title the chart "Measuring Uptake of Blue Solutions in 4 Microclimates."
4. Set up your experiment: Mix a solution of 2 cups of warm water and 12 drops of red food coloring. Place about a half a cup of solution into each of 4 jars that are labeled 1-4.
Make a clean cut on the base of the celery stalk. Next, peel the outer skin of the stalk from top to bottom to create a window to better see the "strings" or vascular bundles. Insert the stalk of celery, large end down, into each jar of solution. Place each jar into the site you have chosen for it.

Divide your class into teams for recording the height of the color at the given time intervals. Come together as a class to record your results on the class chart.

Discussion and Questions:
1. Did you find a fluctuation in temperatures at your different sites when you were looking for sites at the begining of the experiment? Why? What time would be the best time to try this experiment again?
2. Does temperature affect uptake of solutions in celery stalks?
4. If temperature can influence the uptake of a liquid, can you think of other factors that might also influence plants? Make a list of the factors. How would each of them influence plants?
5. How could different microclimates outside affect the plants in them? Could you design an experiment that could test your ideas?
6. Can you graph the results of this experiment?

National Science Education Standards

Science as Inquiry

Plan and conduct a simple investigation. (K-4)

Use data to conduct a reasonable explanation. (K-4)

Think critically and logically to make relationships between evidence and explanations. (5-8)

Scientists use different kinds of investigations depending on the questions they are trying to answer. Types of investigations include describing objects, events, and organisms; classifying them; and doing a fair test (experimenting). (K-4)

Life Science
All organisms must be able to obtain and use resources, grow, reproduce, and maintain stable internal conditions in a constantly changing external environment. (5-8)

Earth Science
The sun provides light and heat necessary to maintain the temperature of the earth. (K-4)

National Math Standards

Data Analysis and Probability
Formulate questions that can be addressed with data and collect, organize, and display relevant data to answer them.

Measurement
Understand measurable attributes of objects and the units, systems, and processes of measurement.

Apply appropriate techniques, tools, and formulas to determine measurements.