PHOTOSYNTHESIS
C 4 PHOTOSYNTHESIS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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stomata are closed and CO2 levels are too low.
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stomata are closed and O2 levels are too low.
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stomata are open and too much water is leaving the plant
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stomata are open and the plant receives too much CO2
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Detailed explanation-1: -Why does photorespiration happen? If it is too hot or dry, plants often close their stomata to prevent water loss. This prevents CO2 from entering the leaf, as well as prevents O2 from exiting. Oxygen builds up inside the leaf and photorespiration happens instead of the Calvin cycle.
Detailed explanation-2: -When the levels of carbon dioxide within a leaf are minimal, photorespiration occurs. This occurs when a plant is forced to close its stomata on hot, dry days to avoid excess water loss.
Detailed explanation-3: -If the stomata is closed, the oxygen from photosynthesis will build up inside the leaf while the carbon dioxide will not get into the leaf. This situation will make the concentration of oxygen inside the leaf higher than carbon dioxide. The rubisco will more likely bind the oxygen. So, the photorespiration happens.
Detailed explanation-4: -In the photorespiration pathway, 6 O2 molecules combine with 6 RuBP acceptors, making 6 3-PGA molecules and 6 phosphoglycolate molecules. The 6 phosphoglycolate molecules enter a salvage pathway, which converts them into 3 3-PGA molecules and releases 3 carbons as CO2.
Detailed explanation-5: -Plants lose the majority of their water through stomata. Thus, they close their stomata at night to prevent excess loss of water through them.