Which statement is accurate about how C ₄ plants are able to survive hot, dry spells during the growing season? A) When the stomata close during the heat of the day, RuBP carboxylase(rubisco), which is located in the bundle sheath cells, is not exposed to the increasing oxygen concentration in the leaf spaces. This prevents RuBP carboxylase from binding to oxygen instead of carbon dioxide. B) When the stomata close during the heat of the day, RuBP carboxylase (rubisco), which is located in the mesophyll cells,is exposed to the increasing oxygen concentration in the leaf spaces. This help facilitate the binding of RuBP carboxylase to oxygen. C) When the stomata are open during the heat of the day, RuBP carboxylase (rubisco), which is located in the bundle sheath cells, is equally exposed to both the carbon dioxide and the oxygen in the leaf spaces. D) When the stomata close during the heat of the day, RuBP carboxylase (rubisco), which is located in the bundle sheathcells,is exposed to the increasing oxygen concentration in the leaf spaces. This help facilitate the binding of RuBP carboxylase to oxygen. E) When the stomata close during the heat of the day, RuBP carboxylase (rubisco), which is located in the bundle sheath cells,is exposed to the increasing oxygen concentration in the leaf spaces. This help facilitate the binding of RuBP carboxylase to oxygen.

Question

Quizplus · Accepted Answer

C4 plants, such as those using the C4 photosynthetic pathway, have adaptations that allow them to survive in hot, dry conditions. One key adaptation is the spatial separation of the initial CO2 fixation and the Calvin cycle. The initial fixation occurs in the mesophyll cells, where an enzyme different from rubisco fixes CO2 into a four-carbon compound. This compound is then transported to the bundle sheath cells, where CO2 is released and then fixed again by rubisco into the Calvin cycle. This mechanism effectively concentrates CO2 around rubisco, reducing its exposure to oxygen and thus minimizing photorespiration, which is more likely to occur at high temperatures when the stomata are closed to conserve water. This is why the statement about rubisco being in the bundle sheath cells and not being exposed to increasing oxygen concentration (due to closed stomata) is accurate.

Which Statement Is Accurate About How C 4 Plants Are

Which Statement Is Accurate About How C ₄ Plants Are