Question

what do the \white light\ (solid red) and \darkness\ (striped orange) bars represent?
a. the solid red bar shows how oxygen volume increases due to photosynthesis, and the striped orange bar shows how oxygen volume decreases due to aerobic cellular respiration and a lack of photosynthesis.
b. the solid red bar shows how oxygen volume decreases due to photosynthesis, and the striped orange bar shows how oxygen volume increases due to aerobic cellular respiration and a lack of photosynthesis.

based on your results, what can you conclude from this experiment?
a. plants exposed to darkness will undergo cellular respiration and produce oxygen.
b. plants exposed to white light will undergo cellular respiration but not photosynthesis.
c. plants exposed to white light will undergo photosynthesis and produce oxygen.
d. plants exposed to darkness will undergo photosynthesis and produce oxygen.

Explanation:

Analyze the effect of light and darkness on oxygen volume

Using the Volumetric Photosynthesis Measurement and Rate of Photosynthesis Calculation knowledge points

• In the presence of white light, plants perform both photosynthesis and cellular respiration. Because the rate of photosynthesis is typically much higher than cellular respiration under bright light, there is a net production of oxygen, causing the oxygen volume to increase.
• In darkness, photosynthesis cannot occur due to the lack of light energy. However, the plant cells continue to perform aerobic cellular respiration continuously to produce ATP, which consumes oxygen and causes the oxygen volume to decrease.
• Therefore, the solid red bar (white light) represents an increase in oxygen volume due to photosynthesis, and the striped orange bar (darkness) represents a decrease in oxygen volume due to aerobic cellular respiration and a lack of photosynthesis. This matches option A for the first question.

Determine plant physiological processes from the experiment

Using the Photosynthesis Chemical Equation and Photosynthesis Reactants knowledge points

• The experimental results show that under white light, oxygen volume increases (indicating active photosynthesis producing oxygen).
• Under darkness, oxygen volume decreases (indicating cellular respiration consuming oxygen without photosynthetic oxygen production).
• This demonstrates that plants exposed to white light undergo both photosynthesis (producing oxygen) and cellular respiration, while plants in the dark only undergo cellular respiration.
• Looking at the choices for the second question, option C states: "Plants exposed to white light will undergo photosynthesis and produce oxygen." This is a direct, valid conclusion supported by the positive change in oxygen volume under the white light condition.

Answer:

Question 1

• (A) The solid red bar shows how oxygen volume increases due to photosynthesis, and the striped orange bar shows how oxygen volume decreases due to aerobic cellular respiration and a lack of photosynthesis. (Correct answer)
• (B) The solid red bar shows how oxygen volume decreases due to photosynthesis, and the striped orange bar shows how oxygen volume increases due to aerobic cellular respiration and a lack of photosynthesis.

Question 2

• (A) Plants exposed to darkness will undergo cellular respiration and produce oxygen.
• (B) Plants exposed to white light will undergo cellular respiration but not photosynthesis.
• (C) Plants exposed to white light will undergo photosynthesis and produce oxygen. (Correct answer)
• (D) Plants exposed to darkness will undergo photosynthesis and produce oxygen.