Name: _____________________________________________________Period: ____
Title: PLANT RESPONSE TO LIGHT LAB
Introduction: Plants are living things that respond their environments, just like animals. One of
the factors that plants are known to respond to is light. Does it make a difference how much
light? What type of light? In this lab you will design a test to find out.
Materials: 2 Plastic cups, soil, 5 popcorn seeds per cup, Sharpie or wax marker,
light sources, colored plastic wrap, ruler, other items you might think of
Procedures:
1. Work with your group to pick a variable to test. Write your hypothesis on the board in an
“if then” statement. When it is approved, you may begin.
2. Fill the plastic cup to the rim with potting soil.
3. Press the soil so that it is firm.
4. Evenly place 5 seeds in the soil.
5. With a pencil eraser, press the seeds 1 – 2 centimeters (1 ½ is best) into the soil.
6. Cover the seeds with soil.
7. Label the cup with your period & condition.
8. Each group will measure the growth of their plants and take notes on the color, condition,
and health of the plants every week. Record the measurements for each group every
week.
Hypothesis
If we _________________________________________________________________
Then_________________________________________________________________
Data
The data you collect will be placed into the tables below. Make sure you also get the
data from the other groups in the class for your graphs. The raw data will be averaged for each
group. To get the average height for your plants each week add all of the plant heights and
divide by 5. Even if the height is zero, add it in and count it. Zero can be a result. Measure in
centimeters.
Gro
up
Observat
ions
Conditio
n
We
ek
1
2
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
Plant 1
Height
Plant 2
Height
Plant 3
Height
Plant 4
Height
Plant 5
Height
Average
Height
5
1
2
3
4
5
Analysis:
1. Graph your plant compared to the control.
Plant Response to Light
Average
Plant
Height in
cm
0
1
2
Week
3
4
5
2. Summarize the class data. Which groups were taller than the control?
Which were smaller:
3. What other observations described the health of the plants:
4. Which condition grew the largest or tallest plants? Why?
5. How would you explain why plants in 24 hours of dark appear the way they do?
6. What surprised you the most about the results?
7. Why do plants need light?
Conclusion: