a) from figure 1a describe the pattern of water loss from the plant and explain why this pattern occurs.
b) using knowledge of the factors that control stomatal temperature and the data in figure 1b, explain the changes in stomatal resistance during the day as shown in figure 1a.
c) From the data in figures 1a and 1b state what type of plant this is, giving reasons.
Figure 1a shows, for a green plant in a controlled environment, the rate of transpiration and the stomatal resistance of leaves, rs, measured over 24 hours
Figure 1b shows the concentration of CO2 inside the leaves of this plant during the day.
See the attached files for graphs.
Answers to your questions with detailed explanations:
a.) The pattern of water loss, which occurs via transpiration (i.e. water vapor loss) as indicated by the open circles on the figure provided, is inversely related to stomatal resistance, or the closing of the stomata. This means that when stomatal resistance increases, transpiration decreases, and as stomatal resistance decreases, transpiration increases. This relationship is even more evident during the daylight hours versus the nighttime hours. The explanation behind this phenomenon can be summarized as follows:
A stoma consists of a pore in the leaf of a plant bordered by a pair of parenchyma cells called "guard cells" which regulate the size of the opening access to the pore. Carbon dioxide and oxygen enter through the opening and are both used by the plant for its survival (carbon dioxide is necessary for the process of photosynthesis to occur and oxygen is ...
A CAM (Crassulacean acid metabolism) plant is clearly inspected. The changes in stomatal resistance during the day are determined.