Final answer:
A mutation that hampers gas exchange in a tree directly impacts the photosynthesis process due to a reduction in carbon dioxide uptake, limiting the Calvin cycle and glucose synthesis.
Step-by-step explanation:
A mutation that prevents a maple tree from efficiently taking gases from the air would most directly affect the process of photosynthesis. During photosynthesis, plants absorb carbon dioxide (CO2) from the air, which is then used in the Calvin cycle to synthesize organic molecules like glucose. If there's a decrease in the uptake of CO2, the Calvin cycle will be affected, leading to a slowdown or complete stoppage of photosynthesis. Without efficient photosynthesis, the production of glucose for the plant's energy and growth is compromised.
Contrary to the process of quickening the Calvin cycle to compensate, the lack of CO2 would lead to a decrease in the rate of photosynthesis. On a broader scale, such a mutation can indirectly affect the growth of the tree since growth is dependent on the sugars produced through photosynthesis. However, the direct effect would be on photosynthesis, not on growth, respiration, or reproduction directly.
Regarding the effect of closed stomata on hot and dry days, it is important to note that this response conserves water but simultaneously restricts CO2 uptake, further inhibiting photosynthesis.