C. ROOTS
1.The Story of the Root
Presentation: (In a story-like manner )
-Invite a group of children to see the presentation. If the children have already studied the leaf,
say: How does the leaf get the water to make the plant food?
-Have a discussion. Do you remember that leaves circulate the water in the cells that make plant
food? Where did that water come from? It was absorbed through the roots. Plants eat with their
heads, and drink with their feet.
-If the children have not studied the leaf, say: How do plants drink?
-Have a discussion. Say: They drink with their feet. Their roots suck the water from the ground.
Water comes up to the other parts of the plant through the roots. This way, roots help drain water
from the ground. Where there is a lot of rainfall and no plants, the ground becomes very swampy.
Because roots have to provide water, they have a special sensitivity to it. Wherever there is water,
roots will seek it out.
2. THE MAIN FUNCTION OF THE ROOT
The main function of the root is to look for water.
Show a plant in a clear jar with absorbent paper inside to better show roots.
Experiment 1 (allow 5-6 weeks)
Roots Grow Towards water
Age: 6-7 years.
Aim: To show that roots search for water.
Materials: A clear shallow pyrex pan, two toothpicks, soil, seedlings, (beans are good) Chart E.
Vocabulary: Germinate-sprout, bud, or put forth shoots.
Procedure:
-Line the pan with ½ inch deep layer of soil, and plant seeds in a row about 3 inches from one
edge of the pan. Place a toothpick at the end of each row, and water the soil where the seeds were
planted.
-After the seeds germinate, water in a line parallel to the row of seeds. Move the toothpicks to
mark where it was last watered. Gradually water them farther and farther away from the spot they
have germinated, marking this spot each time with toothpicks.
-Put a rock in the soil as an obstruction for the roots to go around. (Goes well with the variation
of the experiment which follows.)
-Show Chart E. Say: Where there was no water, the roots did not grow. Just like this tree, the
roots grow toward the water.
Note: Plant the seeds three inches from the end to make this experiment convincing. If they are
planted at the end, they can only go in one direction, and the experiment will be pointless.
Results: The roots will grow along the length of the pan as the water source keeps moving away.
Conclusion: Roots search for water. Hydrotropism-Roots looking for water.
Experiment 2
Roots grow toward water - variation (outdoors)
Age: 6-7 years
Aim: To show that roots grow towards water.
Materials: A clay pot, fast growing seeds like mustard seeds, and water.
Procedure:
Go outside with a small group of children, and dig a hole deep enough for the clay pot to fit into.
Choose a fairly dry area. Plant the seeds around the outside of the pot at the level of the soil and
allow to germinate. Water the inside of the clay pot.
Results: The roots will come above the ground and into the clay pot.
Conclusions: Roots will even go around obstructions in their search for water.
Additional Experiments: Roots will grow towards water.
Materials: Wire basket, cotton/soil, seeds that germinate quickly.
Procedure:
Put cotton on the bottom of the basket, then the soil, then the seeds on top. Place the basket over
something with a lot of humidity (soil of a large plant). The roots will grow down through the
cotton.
Or: Dig a hole and put the wire basket in the hole on top of a tin of water. (Use germinated
seeds). Watch the roots grow towards the water.
3. PARTS OF THE ROOT
Materials: Chart F, Lima Bean root, or another root that has a cap.
Pictures: root parts, root tip
Presentation:
-The part of the root that guides it towards water is called the tip.
-Show Chart F. The tips of the root are really clever and they can get around an obstacle.
Sometimes they can’t get around the obstacle, and they produce an acid.
-If you cut the tip of the root off, it only grows straight. The tip of the root is like the brain of the
root. It has that special sensitivity.
-The root has a cap which protects it, but the parts of the root that actually absorb water are the
root hairs. (Show lima bean root which has sprouted against the wall of a transparent jar lined
with moistened blotter paper.)
4. COLLABORATION BETWEEN ROOTS AND LEAVES
Materials: Chart G********
Presentation:
-Show Chart G. Sometimes leaves and roots work together. It seems as if there is a collaboration.
See how the leaves grow towards the roots?
-There are two types of leaves depicted in this chart.
1. Narrow leaves where the water falls right down to the root.
2. Other leaves that drip water to the root.
5. OTHER FUNCTIONS OF THE ROOT
How Roots Anchor a Plant
Age: 6-7 years
Aim: To show how roots anchor a plant into the ground and hold it vertical.
Materials: A geometric plane into which thumb tacks can be pushed (a corkboard), a pencil, 3-4
pieces of string with loops at the end, 3-4 thumb tacks, and Chart H.
Procedure:
-As those roots are busily searching for water, they create a network of roots. This network holds
and supports the plant in the ground.
-There is something holding that plant down. Show Chart H.
Demonstration:
-Take a pencil, hold it at the tip standing on the cork board, and watch it fall.
-This time attach three pieces of short string at equidistant points around one end.
-Hold the pencil vertically and make it stand up by attaching the strings to the corkboard.
-Say, just as those strings are holding up the pencil, the roots hold up the tree.
Conclusion: Roots anchor a plant to the ground and allow it to stand erect.
OTHER FUNCTIONS OF THE ROOT
How Roots Cling to the Soil
Material: Chart I, tray with seedlings.
Presentation:
-As roots search for water, they are building quite a network underground. Because of this, the
soil clings to the roots. The roots help the soil from being washed away.
-Show Chart I. Say: Here we can see the soil clinging to the roots. It is part of the cosmic task of
the plant to stop erosion. The roots hold the soil, otherwise the rains would wash it away. Roots
hold the soil like a hand and prevent erosion.
Follow-up: Remove a seedling from the tray to show the amount of soil attached to the root.
(Fasciculate roots are more likely to hold soil because of their network formation.)
6. TWO MAIN TYPES OF ROOT
Material: 2 same size jars (1 with soaked bean seed, one with soaked corn
seed), blotter paper, sand, black construction paper, labels.
Preparation: Place one soaked seed in each jar, and line each jar with dampened blotter paper.
Put sand inside the jar. The seed should be placed near the top of the jar. Cover with black
construction paper.
Presentation:
-Show Corn Root. Say: This root is a fasciculate root from the Latin fascis meaning bundle.
Fasciculate roots are very fine and hairy. They are a tough network of roots and are always
found in monocotyledons (grass, clover)
-Show Bean Root: This is called a tap root and it grows right into the ground. (Old English: tap
=to pierce) It is long and tapering with branches on it. Tap roots are found in dicotyledons
(beans, Oak trees, dandelions).
Follow-up: Children can grow plants with different types of roots. They can find as many
specimens as possible.
7. OTHER SENSITIVITIES OF THE ROOT
Materials: 1 mesh basket with string for hanging, sphagnum moss, fast growing seeds, large clay
pot big enough for basket to sit in.
Presentation:
-There is something else about roots that is interesting. Roots have the job of finding water, and
water is in the ground where it is dark. So, the roots have an intense dislike for light. (Up on the
ground, in the light there is no water).
-Line the basket with moss. Place a little soil in the cup area of the moss and some fast growing
seeds. Cover it with a little bit of soil. Put them in a large enough container that the roots can sit
in it. Water the basket, and set in the sun. Wait for seeds to germinate. When it has germinated,
remove the basket from the container and hang the basket in the light.
-The children will get the impression that roots do not like light since the roots will grow back
inside the basket in order to hide from the light.
Note: When roots are in the darkness, they come out. When the basket is removed from the pot
and hung in the light, the roots will grow back into the basket away from the light.
At another time:
Materials: A sample of bean seeds which were planted in a transparent jar using blotting paper
(approximately 3-4 seeds) planted in 3-4 different directions.
Presentation:
-Say: Just as the roots have the sensitivity to grow towards water, they seem to have another
command being given to them. This command tells them to grow straight down. Only when there
is no water straight down, the command is broken.
-Show bean seeds planted in the transparent jar in all directions. This illustrates the downward
growth of the root regardless of the direction of the bean’s placement of the jar.
Illustrations: (pictures)
Note: If the children show an interest, continue. This sensitivity which is so constantly observed
in most types of roots has been given a very interesting scientific name:
Geotropism: plant growth in relation to gravity. Greek: geo = earth and tropikos = to turn.
Hydrotropism: tendency to turn toward moisture. Greek: hydro = water.
Note: The etymology is given to awaken the child’s interest. It should be included as part of the
story. For example, say: This sensitivity which is observed in most roots has been given a very
interesting scientific name…..etc.
8. VARIETIES OF ROOTS
Materials: Pictures of vegetation and various plants which demonstrate the various root types
(Banyan Tree, ferns, orchids). Samples of roots: parsnip, carrot, turnip, radish, white radish,
sweet potato. (Potato is not a root.)
Presentation:
-As with the leaves, we also have a variety of roots. In the parts of the world where the weather is
hot and there is a lot of moisture in the air, some roots don’t grow in the ground. They take their
water from the air by hanging down the branches. These are called Aerial Roots.
-Show a picture of a fern or an orchid. (pictures)
-There are some roots which help the plants in ways other than supplying food. These are called
Root Climbers, and they throw out suckers to help plants stick to the surface they are growing up.
(Show picture of ivy.) (pictures)
-There is another type of aerial root which starts from a branch, grows down to the ground, and
becomes embedded in it. It thickens and supports the branch like a pillar. We call these roots
Pillar Roots. Latin: pila = a pillar. (Show a picture of a Banyan Tree.) (pictures)
-There is another kind of helpful root – the kind that helps prop the plant up. In some swampy
places, they help the plant stand up. These are called Prop Roots, and they support the plant.
They are secondary roots. English: prop = to support. (Show a picture of Screw Pine or maize.)
(pictures)
-Some of the roots have the task of storing food - they are so big they are almost swollen with
food. They are called Swollen Roots. English: swell = to increase in volume. (Show a parsnip and
a carrot.) (pictures) These are both conical roots. Latin: conus = a cone (show turnip) (pictures)
-This is another root and it is called napiform. Latin: napus = a turnip. (Show a radish.)
(pictures) Say: This is also a napiform.
-Another root is the fusiform root which tapers at each end in the shape of a spindle. (Show a
white radish.) (pictures) Latin: fusus = a spindle
-(Show a sweet potato.) (pictures) This is called a tuberous root. Latin: tuber = from tumere =
to swell
Follow-up activities : The Root
1. Investigate root types in gardens you have planted. (plant radishes, corn)
2. Visit a botanical garden, a local grocery store, an orchard.