Pulling the Water Chain: Grades K-4
Pulling the Water Chain
Educational Activity: Grades K-4
Time: One 60-minute class period
Overview:
In this activity, students learn about the stems of plants and capillary action in taking up
water.
Note: This lesson, Pulling the Water Chain, is one in a series of lessons introducing basic
plant parts and functions. Other lessons cover root structure and function, flower anatomy,
seed function and dispersal, and “breathing” or the exchange of gases in leaves.
Integration with Project BudBurst
Elementary school students participating in Project BudBurst study plants in their
schoolyard environment and learn to make careful observations of the timing of leafing,
flowering, and fruiting of selected plants. In conjunction with teaching students to make
observations of living plants, teachers may also introduce basic plant anatomy, a topic
typically covered at this age. The lessons in this series on plant parts and function may be
used as an introduction to participation in Project BudBurst, to help set the stage for what
students will be observing. Alternatively, teachers may use these lessons in between
times students make outdoor observations to extend their understanding of what they are
observing. For example, as students observe flowering, teachers may use the lesson
Operation Flower Dissection to help students understand the structure and function of
flowers.
Learning Outcomes:
Students will be able to:
 Identify the stem structure in a plant
 Compare the movement of water in celery stalks with and without leaves
 Describe how water moves through a plant’s stem
Materials:
 Fresh bunch of celery with leafy tops
budburst.org
A Project BudBurst Educational Activity
http://www.budburst.org/educators/pdf/PBB_waterchain.pdf
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© 2016 Chicago Botanic Garden. All rights reserved. One of the treasures of the Forest Preserves
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Pulling the Water Chain: Grades K-4
 Small bucket or tub filled with about 6 inches of water
 Red or orange food coloring
 Knife and cutting surface
 Ruler
Education Standards: Available at:
http://budburst.org/educators/pullingchain_sg.php
Activity
1) Tell student they are going to conduct an experiment to learn more about how plants
take up water using capillary action. Define capillary action - the ability of a substance
to draw a liquid upwards against the force of gravity.
2) Cut off the bottom inch of the celery bunch while it is submerged in the tub of water.
Stand the bunch upright and then remove all the leaves from half of the stalks. The
other half, with the leaves intact, will serve as a comparison or control. Finally, add
food coloring to the water.
3) Have students hypothesize how capillary action might be different between stalks with
leaves and stalks without. For example ask students “Do leaves make a difference in
the speed of capillary action?” List their hypotheses on the board or a flipchart,
indicating how many students chose each one. Have students create a bar graph
showing this information.
4) Place the celery tub in a sunny location and remove two stalks of similar size every 15
minutes – one with leaves and one without. Cut each stalk in five-centimeter sections,
from the bottom edge up, until no color can be seen in the celery. For each of the two
stalks, help students estimate how many centimeters up from the bottom the color
traveled in that amount of time, and record this on the board or flipchart. Celery stalks
with leaves should show color traveling further up the stalk in the same amount of
time. Continue until no stalks remain or until the colored water has been siphoned to
the top of at least one stalk.
5) Have students evaluate their hypothesis and decide which one was supported by the
results in the experiment. Do leaves make a difference in the speed of capillary
action? Celery stalks with leaves have a greater amount of transpiration. Water
leaving the plant through the leaves helps pull more water into the plant and up the
stems.
budburst.org
A Project BudBurst Educational Activity
http://www.budburst.org/educators/pdf/PBB_waterchain.pdf
Page 2 of 3
© 2016 Chicago Botanic Garden. All rights reserved. One of the treasures of the Forest Preserves
of Cook County.
Pulling the Water Chain: Grades K-4
Suggested Extension Activities
 Use two bunches of celery in this activity. Put the second bunch in a separate bucket
of water with one or two cups of sugar instead of food coloring. Remove only enough
leaves to allow students a chance to taste them. When the main activity is finished,
have students taste the remaining celery leaves on the second bunch. They will be
able to taste the difference between the leaves before and after the water arrives.
Explain that the sugar is carried by the water up the celery stalks in the same way that
minerals and other nutrients are carried by groundwater up the stems of rooted plants.
 Set a growing plant on a windowsill. Mark a line on the stem with a permanent marker
5 centimeters above the soil surface. Observe the location of the mark after several
weeks. Has the plant grown bigger? Has the location of the mark changes? Why not?
(Plants grow cells from the tip of the plant, not the base.)
Background Information
A stem is the major above-ground part of a plant. It supports the plant, usually growing
upward. Stems contain a system of tubes which carry water and minerals throughout the
plant. Food from the leaves of the plant travels down the stems to the roots. Stems also
store food.
Sometimes plant stems cannot hold up plants. These stems don’t have any rigid
strengthening cells, or at least not very many of these cells. These plants are called vines
and they depend on other strong plants or structures to go up.
Student Assessment Suggestions:
Teachers may have students make drawings of the results of the class experiment,
showing stems with and without leaves and which one had faster capillary action drawing
water up the stem.
Source: Adapted from Exploring the Native Plant World, developed by the Lady Bird
Johnson Wildflower Center in Austin, Texas and Teaching Plants from Root to Seed,
developed by the Denver Botanic Gardens in Denver, Colorado
This teacher resource was made possible, in part, by support from the National
Geographic Education Foundation.
budburst.org
A Project BudBurst Educational Activity
http://www.budburst.org/educators/pdf/PBB_waterchain.pdf
Page 3 of 3
© 2016 Chicago Botanic Garden. All rights reserved. One of the treasures of the Forest Preserves
of Cook County.