Final answer:
If H2O was removed from plants' environment, photosynthesis would be hindered, leading to decreased energy production and plant growth. Eventually, plants would wilt, disrupting food chains and ecosystems, as water is crucial for various plant functions.
Step-by-step explanation:
If H2O was removed from the plants' environment, several key processes necessary for plant survival and growth would be disrupted. Firstly, without water, plants would be unable to perform photosynthesis effectively because water is a raw material for the process. Specifically, a lack of water would prevent H+ and NADP+ from forming NADPH, which is essential for the synthesis of glucose. Without glucose, plants would not be able to produce the energy needed to support various life functions. Furthermore, in hot and dry conditions, plants close their stomata to conserve water, but this also limits the uptake of CO2, which is another key ingredient for photosynthesis. As a result, the rate of photosynthesis would significantly decrease, affecting the plant's growth and survival.
In a scenario where Earth loses its water vapor, as projected to happen about 1 billion years from now, plants would permanently wilt due to the inability to extract water from soil, with soil dryness reaching levels that plants cannot survive. This would cause a collapse in the food chain, as animals and birds that rely on photosynthetic organisms would be affected, oxygen levels would deplete, and aquatic ecosystems would be drastically altered.
Overall, water is essential for plants not just for photosynthesis but also for maintaining cellular structure, nutrient transport, and temperature regulation.