GENERAL KNOWLEDGE

Detailed explanation-1: -The fact that C3 plants respond to higher CO2 concentration by showing increased rates of photosynthesis leading to higher productivity has been used for some greenhouse crops such as tomatoes and bell pepper. They are allowed to grow in carbon dioxide enriched atmosphere that leads to higher yields.

Detailed explanation-2: -It has been suggested that increased [CO2] will increase water use efficiency (WUE) of C3 species, because it causes a reduction in transpiration rate and an increase in CO2 assimilation rate of the plants.

Detailed explanation-3: -Due to their reduced rate of photorespiration and high rate of photosynthesis, C4 plants are more efficient than C3 plants. The main enzyme of carbon fixation in the Calvin cycle is RuBisCO. It shows an affinity for both CO2 and O2.

Detailed explanation-4: -C4 photosynthesis is more efficient than C3 photosynthesis in warmer climates, where yield potential is high. The lower photosynthetic efficiency in C3 plants is due to a dual activity in the enzyme that fixes CO2, Ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO; Brown et al., 2011).

Detailed explanation-5: -Under high temperature, high light, and the current CO2 concentration in the atmosphere, the C4 pathway is more efficient than C3 photosynthesis because it increases the CO2 concentration around the major CO2 fixating enzyme Rubisco.