NAME:__________________________________________ PER:_________ DATE:_________________ SCORE:____________
Biology L.18.7 Photosynthesis Independent Practice (10 points)
DIRECTIONS: Read all questions carefully and write all answers in COMPLETE SENTENCES. Be detailed in your responses and
justify all your answers. Your work will not be graded if you do not write in complete sentences.
1. Write the formula for photosynthesis in the space below. Place a circle around each reactant. Place a box around each
product. Label what each molecule is in the formula (for example CO2 = carbon dioxide).
2. In which cellular organelle does photosynthesis take place? ______________________________________
3. Describe three things a scientist could do to decrease the rate of photosynthesis:
a. _____________________________________________________________________________________________
b. _____________________________________________________________________________________________
c. _____________________________________________________________________________________________
4. A scientist wants to investigate the effect of water availability on the rate of photosynthesis in a plant species. In an
experiment the scientists will expose the same type of plant to different amounts of water and measure the amount of gas that
is produced with a special sensor. Describe what you would expect the scientist’s sensor to be measuring when it is collecting
data. Explain why.
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5. A scientist filled a greenhouse with one type of plant species. Every hour for 1 day the scientist measured the concentration of
carbon dioxide in the air. He found that there was a higher level of carbon dioxide in the air between the hours of 8pm and
6am. Provide one possible explanation for these results and be sure to justify your explanation.
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6. Answer the following questions based on the graph to the right.
a. What is the independent variable? ________________________
b. What is the dependent variable? __________________________
c. What is the relationship between temperature and the rate of
photosynthesis?
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d. At what range of temperatures does this plant produce the most
sugars?
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7. A group of students conducted an experiment for the science fair where they investigated the rate of photosynthesis. They
went out to a garden of various plants and measured the carbon dioxide concentration. They started by measuring the
concentration of carbon dioxide 5 meters from the garden and moved 1 meter closer each trial. The closer they moved to the
garden the lower the carbon dioxide concentration became.
a. Explain why the lowest carbon dioxide concentration occurs closest to the garden. Be sure to include a biological
process in your answer.
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b. Describe how the concentration of oxygen in the atmosphere should compare to the concentration of carbon dioxide
assuming all other factors are kept the same.
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8. Design an experiment using the steps below to figure out how some factor (i.e. amount of sunlight, amount of CO2, etc.)
affects the rate of photosynthesis.
a. What is the scientific question: ____________________________________________________________________
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b. Write a brief procedure for how you could test your question. Be sure to identify your independent variable,
dependent variable, and controls (remember, the independent variable is what the experimenter is changing/manipulating)
Independent variable = ____________________________ dependent variable = ____________________________
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c. Based on your knowledge of photosynthesis what do you expect the results of your experiment to be? Be detailed in
your answer and be sure to justify it with your knowledge of photosynthesis!
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