Why do plants have tendrils?

Why aren't all plants C4 plants?

• C4 plants don't perform photorespiration; therefore, they can keep their stomata closed longer when the weather is warm. This seems to be an advantage. Why aren't all plants C4 plants? C4 plants can't take in any oxygen while the stomata are closed. C4 plants must use ATP to shuttle CO2 to the bundle-sheath cells. C4 plants can't take any CO2 while the stomata are closed. C4 plants can't take in any water while the stomata are closed.

• Answer:

  C4 plants must use ATP to shuttle CO2 to the bundle-sheath cells. This question is C4 metabolism NOT CAM metabolism. C4 plants have their stomates open in the day and closed at night. There are anatomical differences between typical C3 and typical C4 plants. C4 plants usually perform carbon fixation in multiple cells. [Recent discoveries have shown that C4 metabolism can be completed in single cells (Borszczowia aralocaspia; Bienertia cycloptera, and diatoms) C4 plants have a competitive advantage in hot, dry climates, not everywhere.