Mrs. Keadle JH Science
Name__________________________________ period _____
date assigned_____________ date due ______________ date returned _____________
Forces in Living Things
Lab 1: Seedlings in View
In this lab, each class is going to grow a seedling to watch the effects of gravitropism on a young,
growing plant.
Hypothesis: Finish this sentence to describe what you think will happen to the seedling:
I think the roots will________________________________________________________
________________________________________________________________________,
and the stems and leaves will ________________________________________________
________________________________________________________________________ .
Materials:
clear tube containing “crystal clay”
tube stand
seed packet (sunflower, miniature pumpkin and morning glory)
spring water
Procedure:
1. Assemble the stand and place it on the tube (this will already be done for you).
2. Using spring water, fill the clear plastic tube halfway.
3. Wait 20 to 60 minutes. If any of the crystals are still exposed above the water line, add more water
one teaspoon at a time. Re-Check every 30 minutes and add water as needed until the crystals have
stopped expanding. If the crystals reach the top of the tube, remove some until it is no more than ¾
full. If there is too much water, pour some off of the top.
4. Add the seeds. Do not bury them and make sure that the water level is high enough to keep the
seeds moist, but not soaked, during the first 3 days.
The Sleeping Seed
So now you have your seeds in the crystal clay and they’re just lying there! Nothing’s happening! Well,
actually, lots of things are happening that you just can’t see right away. Right now, the seeds are
dormant (almost like sleeping) but the moisture will trigger them to start their growth cycle. This
process is called germinating. Once the water absorbs into the seeds, it sends a signal to tell the seed it
can start to grow.
The part of the seed that you see right now is called the seed coat. It protects the young plant. Inside of
the seed coat is the real growing part of the baby seed.
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Forces In Living Things
Mrs. Keadle JH Science
Diagram the full set-up. Label the seed coat.
5. Put the set-up in a bright, cool place with the cap off. The cap must stay off because the seedlings
need____________________________________________________________________________
6. Add water as needed to keep the water level just below the top of the crystals.
7. After 1-2 days, take out any seeds that have not germinated.
It Starts…
Watch the seeds for changes. In a day or two the seed coats will start to split, and you’ll see the root tip
sticking out. Scientists call that part the radicle. Watch it dive into the crystal clay to become the main
root. Eventually, it will branch out to become the root system.
First Leaf…
The radical drinks up water so that the plant can start to grow. As the stem grows
and the seed coat splits off, you will see the first new green leaf. The first leaf is
called a cotyledon. Once the plant begins to grow, it needs water, carbon dioxide,
and sunlight. The leaves absorb carbon dioxide through tiny opening on the
underside of the leaf called stomata. Sunlight can pass through the leaf and is
collected in the chlorophyll of the green parts of the plant. Water is absorbed
through the roots and in some cases the leaves.
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Forces In Living Things
Mrs. Keadle JH Science
Plants need carbon dioxide, water and sunlight to complete the process of ______________________
Diagram the young seedling. Label the radical and cotyledon. Also label where water, sunlight and
carbon dioxide enter the young plant.
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Forces In Living Things
Mrs. Keadle JH Science
Question
Observation
Communicate Results
to add to experience
linking idea
Hypothesis
Predict
hypothesis
proven
correct
hypothesis
not
confirmed
try another
Interpret the Data
hypothesis
needs
modification
Plan an Investigation
Observation
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Forces In Living Things
Mrs. Keadle JH Science
Lab 2: Geotropism
In this lab, we will observe how gravity can affect corn seedling growth.
Materials:
4 corn seedlings
paper towel
petri dish
tape
cotton balls
tap water
removable marker
Procedure:
1. Take four soaked corn seeds, and place them in the bottom of a petri dish with the seed ends facing
toward the center. A corn seed should be placed on the 12, 3, 6 and 9 o’clock positions of the petri
dish.
2. Cut paper towel to fit the inside of the petri dish.
3. Using the spray bottle, dampen the paper towel circle. Do not get it so wet that it drips.
4. Carefully cover the corn seeds with the paper towel as to not disturb the positions of the corn seeds.
5. Use 4 cotton balls to pack the petri dish to secure the seeds.
6. Close the petri dish and tape the lid in place.
7. Diagram the petri dish set-up at the beginning of the lab and the end
8. Write the group member names on a small piece of paper and tape it to the back of the petri dish.
9. Place the petri dished vertically in a dark place such as a closet or cabinet.
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Forces In Living Things
Mrs. Keadle JH Science
Diagram and describe in complete sentences what the corn seeds now look like and what happened to
them.
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
1. Describe the direction in which the roots of the seeds grew__________________________________
__________________________________________________________________________________
__________________________________________________________________________________
2. What force are the roots responding to?__________________________________________________
3. Why do roots grow down?_____________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
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Forces In Living Things
Mrs. Keadle JH Science
Question
Observation
Communicate Results
to add to experience
linking idea
Hypothesis
Predict
hypothesis
proven
correct
hypothesis
not
confirmed
try another
Interpret the Data
hypothesis
needs
modification
Plan an Investigation
Observation
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Forces In Living Things
Mrs. Keadle JH Science
Lab 3: Emergence of Seedlings
In this lab, we will observe how much force young bean seedlings can exert.
Materials:
4 soaked pinto bean seeds
3 oz paper cup
6 tablespoons of plaster of paris
craft stick
water
paper towel
Procedure:
1. Write the group member names on a piece of paper and tape to the cup.
2. In the 3oz paper cup, use the craft stick to mix 6 tablespoons of plaster of paris with enough water to
make a mixture with the consistency of pancake batter.
3. After mixing the plaster, push the 4 soaked pinto beans into the surface of the plaster so that over
half the bean is in the plaster.
4. Soak a paper towel with water and place over the top of the beans in the cup.
5. Keep the paper towel wet throughout the investigation.
Using the Bean Review, label the diagram of the bean parts.
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Forces In Living Things
Mrs. Keadle JH Science
Dissect a bean. Diagram and describe in complete sentences what you see
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Diagram and describe what happened after the beans were able to sprout.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
1. What affect did the seeds have on the plaster?____________________________________________
__________________________________________________________________________________
2. Why do you think this occurred?_______________________________________________________
__________________________________________________________________________________
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Forces In Living Things
Mrs. Keadle JH Science
Question
Observation
Communicate Results
to add to experience
linking idea
Hypothesis
Predict
hypothesis
proven
correct
hypothesis
not
confirmed
try another
Interpret the Data
hypothesis
needs
modification
Plan an Investigation
Observation
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Forces In Living Things
Mrs. Keadle JH Science
Lab 4: Turgor Pressure
In this lab, we will observe how water can affect the rigidity of a plant.
Materials:
strips of potato
salt
Procedure:
1. Soak some strips of potato in salt water and some in fresh water overnight in a refrigerator.
2. Take one potato strip that was soaked in salt water and that was soaked in fresh water.
3. Bend each strip until it breaks.
1. Describe the differences between the two strips___________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
2. What force caused these changes?______________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
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Forces In Living Things