PHOTOSYNTHESIS
THE CALVIN CYCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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fix CO2 into organic acids during the night when temperatures are cooler.
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fix CO2 into by combining it with RuBP in the Calvin cycle.
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obtain CO2 through their roots during the day.
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fix CO2 into organic acids in the mesophyll cells, which do not rely on stomata. HIDE ANSWER
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Detailed explanation-1: -In CAM plants, the stomata in the leaves remain shut during the day to reduce transpiration through evaporation, but open at night to collect carbon dioxide (CO2).
Detailed explanation-2: -In CAM photosynthesis, stomatal behaviour reverses; atmospheric CO2 is fixed at night and stomata are closed during the day. The initial CO2 fixation is performed by the enzyme phosphoenolpyruvate (PEP) carboxylase. CO2 is fixed into 4-carbon compounds, primarily malate, and stored in vacuoles as an acid.
Detailed explanation-3: -Unlike plants in wetter environments, CAM plants absorb and store carbon dioxide through open pores in their leaves at night, when water is less likely to evaporate. During the day, the pores, also called stomata, stay closed while the plant uses sunlight to convert carbon dioxide into energy, minimizing water loss.
Detailed explanation-4: -CAM pathway can be seen in desert plants and epiphytes (i.e. plants that live on other plants). Unlike C3 and C4 plants, these plants keep their stomata closed during day and open it during night for fix CO2 in the form of malate and releases O2. They do it so, to prevent loss of water due to sunlight.