The C4 photosynthetic pathway evolved as an adaptation to minimize photorespiration. What is photorespiration and why does it occur?  (4 points) Explain how the C4 pathway minimizes photorespiration compared to C3 photosynthesis. (3 points) Given this information, how should C3 and C4 plants respond to elevated temperatures? (3 points)

Damage to the proteins of the photosystems by excess light is known as_________________.

The _________________ cells contain Rubsico in C4 plants. 

_________________ is an enzyme that has a dual affinity for CO2 and O2 

The following figure shows the response of stomatal conductance to changing water potential for two different tree species. What is the difference between isohydric and anisohydric stomatal behavior? (4 points) Which data (1-open circles; 2-closed circles) likely represent isohydric and anisohydric species? (2 points) How could plant mortality result from either of these strategies? (4 points)

Air bubbles that form in the xylem under high tensions are known as _____________.

Describe the driving forces for water movement for each of the following steps in the SPAC: from the bulk soil to the roots, through the xylem, and from the leaf to the atmosphere (6 points). How does xylem anatomy impact this movement? (4 points)

Pores that allow gas exchange in leaves are known as__________________. 

_________________ is an enzyme that has an affinity only for CO2. 

What body region is labeled 11?