How Did that Plant Get Here? Name______PD ___
Directions: Use the following information to answer questions 1 through 12.
Demetri did the following investigation in a local college laboratory to see how carbon dioxide (CO2) affects plant growth.
Demetri grew bean plants in growth chambers where he could control the amount of oxygen (O2) and CO2 in the air around the plants. He grew the bean plants in water with mineral nutrients instead of soil. Demetri had to completely dry the plants in an oven to get the plants’ dry mass.
Question: What is the effect of different amounts of carbon dioxide (CO2) in air on the dry mass of bean plants?
Hypothesis: As the concentration of CO2 in air increases, the dry mass of bean plants will increase because bean plants use CO2 for growth.
Materials:
bean plants with the same mass
water with mineral nutrients
identical growth chambers labeled A, B, and C
containers of CO2 and O2 gas
monitors for CO2 and O2 gas
oven
balance
Procedure:
1. Put 12 bean plants into Chamber A as shown in the Investigation Setup diagram. Do the same to Chambers B and C.
2. Make sure each chamber receives the same amount of light and water. Keep the chambers at a constant temperature and pressure.
3. Adjust the O2 level of the air in each chamber to the normal amount of O2 in the atmosphere.
4. Remove 4 bean plants from each chamber. Dry the plants in the oven and measure their
dry masses.
5. Calculate and record the average dry masses as Day 1.
6. Set and keep the CO2 level in Chamber A at 0 parts per million (ppm), Chamber B at 700 ppm,
and Chamber C at 1,400 ppm.
7. Repeat steps 4 and 5 for Day 7 and Day 14.
Data:
Amount of CO2 vs. Bean Plant Dry MassAmount of CO2
(parts per million) / Bean Plant Dry Mass
(averages in grams)
Day 1 / Day 7 / Day 14
0
(Chamber A) / 0.8 / 0.8 / 0.8
700
(Chamber B) / 0.8 / 4.5 / 8.6
1,400
(Chamber C) / 0.8 / 4.7 / 10.8
Note: Day 1 masses were determined before CO2 levels were adjusted.
1. Which part of the investigation increases the validity of the investigation?
o A. Final bean plant dry mass and amount of light
o B. Amount of CO2 and type of growth chamber
o C. Growth of plants and amount of O2
o D. Type of plants and amount of O2
2. Which part of the investigation increases the reliability of the investigation?
o A. Measured four plants each time for repeated trials
o B. Kept the volume of oxygen gas containers the same
o C. Changed the carbon dioxide concentration in each chamber
o D. Used the same type of mineral nutrients added to the water
3. Which variable was the manipulated (independant) variable in this investigation?
Write your answer in the box.
4. After completing the investigation Demetri discussed further questions about the study with his lab partners. Of the questions they considered, which question could be answered through a scientific investigation?
o A. What effect does the amount of sunlight on a plant have on the growth of a bean plant?
o B. How does carbon dioxide and oxygen become part of the earth’s atmosphere?
o C. What can we learn from studying the roots and leaves of the bean plant?
5. As countries around the world begin to develop and increase their need for transportation, more people will drive cars. This would lead to an increase of carbon dioxide in the atmosphere. Based on the Amount of CO2 vs. Bean Plant Dry Mass data table, what could be an unintended consequence of the increased use of automobiles?
o A. The plants and trees in the city would be smaller.
o B. The plants and trees would grow but at a slower rate.
o C. The plants and trees in the city would grow and become larger.
o D. The plants and trees in the city would continue to grow at the same rate.
6. The roots of the bean plants take up water from the soil. What structure regulates the flow of materials into and out of the cells of the root?
Write your answer in the box.
7. Which fact about bean plants shows how plants are different than animals?
o A. Plants can reproduce.
o B. Plants require water to survive.
o C. Plants can use light energy to produce food.
o D. Plants have a cell nucleus containing DNA.
8. The plant investigation set up that Demetri created is a simplified model of a complex ecosystem. What difference between the plant investigation system and a real ecosystem should be considered when interpreting the results?
o A. The plant growth may be limited by the size of the chambers used in the investigation.
o B. The plant growth may be limited by the color of the chamber lid used in the investigation.
o C. The plant growth may be caused by the manufacturer of the gas monitors used in the investigation.
o D. The plant growth may be caused by the size of the containers used to supply the gas in the investigation.
9 Write a conclusion for this investigation.
In your conclusion, be sure to:
· Answer the investigative question.
· Include supporting data from the Amount of CO2 vs. Bean Plant Dry Mass table.
· Explain how these data support your conclusion.
· Describe a scientific reason to explain the trend in data table.
Question: What is the effect of different amounts of carbon dioxide (CO2) in air on the dry massof bean plants?
10. Describe two energy transfers that happened in the diagram in the box.
In your description, be sure to:
· Identify the forms of energy before and after each energy transfer.
· Describe where each energy transfer happened.
You may use words, labeled pictures, and/or labeled diagrams on the diagram below.
One transfer:Another transfer:
11. Plan a controlled investigation to answer the question printed in the box. You may use any materials and equipment in your procedure.
In your procedure, be sure to include:
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· logical steps to do the investigation
· two controlled variables
· one manipulated variable
· one responding variable
· how often measurements should be taken and recorded
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Question: What is the effect of different amounts of mineral nutrients on the height of bean plantsgrown in CO2 rich atmosphere?
Procedure:
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