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Transpiration is the movement of water through a plant and out of its leaves and other aerial parts into the atmosphere. This movement is driven by solar energy. [4] In the tallest trees, such as Sequoia sempervirens, the water rises well over 100 metres from root-tip to canopy leaves. Such trees also exploit evaporation to keep the surface cool.
This evaporation increases the tension on the water menisci in the cell walls and decreases their radius, thus exerting tension in the cells' water. Because of the cohesive properties of water, the tension travels through the leaf cells to the leaf and stem xylem, where a momentary negative pressure is created as water is pulled up the xylem ...
Yet another theory is that the heat helps protect against frost damage, allowing the plant to germinate and sprout earlier than otherwise. For example, the skunk cabbage generates heat, which allows it to melt its way through a layer of snow in early spring. [4] The heat, however, is mostly used to help spread its pungent odor and attract ...
Simplified control circuit of human thermoregulation. [8]The core temperature of a human is regulated and stabilized primarily by the hypothalamus, a region of the brain linking the endocrine system to the nervous system, [9] and more specifically by the anterior hypothalamic nucleus and the adjacent preoptic area regions of the hypothalamus.
If there is too little water then tissues will dehydrate and the plant may die. If the soil becomes waterlogged then the soil will become anoxic (low in oxygen), which can kill the roots of the plant. [8] The ability of plants to access water depends on the structure of their roots and on the water potential of the root cells.
Over time, the snowpack on the ground goes through a cycle of mild melting during the day and refreezing over night, causing the snowflakes to lose their shape and the space between their arms.
Smoke smudges the horizon, blurring the boundary between trees and sky. These simulated graphics are generated in part by algorithms that account for factors like humidity, terrain, wind, fuel ...
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature as its own body temperature, thus avoiding the need for internal thermoregulation.