After reading the paragraph below, answer the questions that follow.
The graph below shows records of temperature (light gray line) and CO₂ (dark gray line) over the past 1,000 years. CO₂ is recorded in parts per million (ppm).

-If the trends shown in the graph continue, how might this affect photosynthesis?
A)Photorespiration may increase, leading to an increase in photosynthetic production of sugar.
B)Photorespiration may increase, leading to a decrease in photosynthetic production of sugar.
C)C₄ and CAM plants would be unable to photosynthesize.
D)There would be no effect on photosynthesis, since CO₂ and temperature are stable.

Question

After reading the paragraph below, answer the questions that follow.
The graph below shows records of temperature (light gray line) and CO₂ (dark gray line) over the past 1,000 years. CO₂ is recorded in parts per million (ppm).
 
-If the trends shown in the graph continue, how might this affect photosynthesis?
A)Photorespiration may increase, leading to an increase in photosynthetic production of sugar. 
B)Photorespiration may increase, leading to a decrease in photosynthetic production of sugar. 
C)C₄ and CAM plants would be unable to photosynthesize. 
D)There would be no effect on photosynthesis, since CO₂ and temperature are stable.

Quizplus · Accepted Answer

The graph shows an increase in CO₂ levels, which would lead to an increase in photorespiration and a decrease in photosynthetic production of sugar. This is because in high CO₂ environments, plants have less of a need to take in CO₂, so they close their stomata. However, when the stomata are closed, the O₂ concentration inside the plant exceeds the CO₂ concentration, which causes photorespiration.

After Reading the Paragraph Below, Answer the Questions That Follow