Graphs are useful for presenting data. One type of graph is a line graph. The line graph below was presented on p. 2 of this lesson. It shows measurements of light, carbon dioxide, water, and temperature. All measurements were taken in the same greenhouse where many plants were being grown. The y axis has an unusual label. It doesn't have numbers. This is because levels of light, carbon dioxide, water, and temperature would need different scales and units. However, it does show relative changes over time. For example, notice that the carbon dioxide level goes down significantly in the middle section of the day. 1. What is the most logical reason that the carbon dioxide level went down during the middle of the day? Use the graph to help you decide. It will also be helpful to think about what you have learned in previous units. (1 point) Responses The carbon dioxide level decreases in the middle of the day because the greenhouse was flooded with steadily increasing levels of water. The carbon dioxide level decreases in the middle of the day because the greenhouse was flooded with steadily increasing levels of water. The carbon dioxide level decreases in the middle of the day because there is no light in the greenhouse, so photosynthesis can't be performed. The carbon dioxide level decreases in the middle of the day because there is no light in the greenhouse, so photosynthesis can't be performed. The carbon dioxide level decreases in the middle of the day because the temperature

Answer 1

increases, causing the plants to use more carbon dioxide for respiration.