Question

In C3 plants the conservation of water promotes _____.

Answer 1

In C3 plants, water conservation is achieved by closing the stomata during drought conditions and reducing loss through transpiration. Desert plants like cacti have evolved to fix CO2 at night and use it for photosynthesis during the day to minimize water loss. These adaptations are crucial for survival in arid environments.

Step-by-step explanation:

In C3 plants, the conservation of water promotes various strategies to cope with dry conditions. For instance, during drought conditions, the stomata close to conserve water, thereby slowing down the transpiration process. This is essential as it helps to minimize water loss through evaporation. Furthermore, in extremely hot temperatures, where the amount of water in leaves decreases, these plants are less likely to lose water through evaporation.

Desert plants, such as cacti, are examples of plants that have evolved specialized mechanisms to deal with water scarcity. These plants have adaptations that allow them to open their stomata at night to fix carbon dioxide into a temporary storage molecule, reducing water loss during the cooler temperatures. During the day, with stomata closed, they use the stored carbon dioxide for photosynthesis, thus conserving water. Water conservation is of utmost importance in such harsh environments and can dictate the survival of the plant species.

Answer 2

Photorespiration

Step-by-step explanation:

RuBisCo is the enzyme that catalyzes the first reaction of the Calvin cycle which in turn is a rate-limiting step. Photorespiration is the process during which the enzyme RuBP carboxylase/oxygenase (RuBisCo) catalyzes the reaction between oxygen and ribulose 1,5-bisphosphate to form 3-phosphoglycerate and 2-phosphoglycolate.

These two products are useless for the metabolism of cells. Photorespiration occurs since the RuBisCo enzyme has an affinity for both CO2 and oxygen. When CO2 is not available, as it occurs when plants close stomata during hot dry days to prevent water loss, photorespiration takes place. Therefore, stomatal closing in C3 plants to prevent water loss promotes photorespiration.