Geotropism explains which of the following phenomena?

a water collects in rock crevices, freezes and expands, and shatters the rock.
b a seed is planted upside-down, but the roots still grow in the direction of gravity. c two tectonic plates move toward each other, collide, and form a mountain.
d after a natural disaster, all animal life disappears from the affected area.

High-pressure liquid chromatography (hplc) is a method used in chemistry and biochemistry to purify chemical substances. the pressures used in this procedure range from around 500 kilopascals (500,000 pa) to about 60,000 kpa (60,000,000 pa). it is often convenient to know the pressure in torr. if an hplc procedure is running at a pressure of 1.03×108 pa , what is its running pressure in torr?