Answer:
Pressure with Height: pressure decreases with increasing altitude. The pressure at any level in the atmosphere may be interpreted as the total weight of the air above a unit area at any elevation. At higher elevations, there are fewer air molecules above a given surface than a similar surface at lower levels.In addition, gravity is weaker at the equator due to centrifugal forces produced by the planet's rotation. It's also weaker at higher altitudes, further from Earth's centre, such as at the summit of Mount Everest
1-<span>auxins in the lower sides of stems cause cell elongation that bends the stem upright
2-</span><span>thigmotropism.
3-</span><span>phototropic and gravitropic
4-</span><span>the production of anthocyanin and the breakdown of chlorophyll.
5-</span><span>exposing the plant to a brief period of light in the middle of the night</span>