Answer:
Guard cells perceive and process environmental and endogenous stimuli such as light, humidity, CO2 concentration, temperature, drought, and plant hormones to trigger cellular responses resulting in stomatal opening or closure.
Explanation:
What is the main source of downward convection<span> flow in the mantle called? The downward sliding characteristic of ridge-push is the result of what? </span>What causes<span> the </span>thermal convection that drives plate motion<span>? Is it the downward arm of convective flow in the mantle?
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</span>The heat driving<span> mantle </span>convection<span> has three sources. "Primordial" </span>heat<span> (left over from the accretion and differentiation that led to the formation of Earth's core) contributes 20 to 50% of the </span>heat<span>. ... Mantle </span>convection<span> is the main mechanism by which this </span>heat<span> escapes from the interior of Earth.
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Vesicles form naturally during the process of secretion(exocytosis), uptake (phagocytosis and endocytosis) and transport of materials within the cytoplasm. Alternatively, they may be prepared artificially, in which case they are called liposomes.
The make energy from sunlight through photosynthesis.