Most of the water reaching the collecting ducts is not reabsorbed
Answer:
Molecules which move against the concentration gradient across the cell membrane employ the mechanism of active transportation.
Explanation:
Normally, permitted molecules moves across the cell membrane of the cell by the process of diffusion and osmosis. This is used when molecules move from hypertonic region to hypotonic region (if ions) and hypotonic to hypertonic (if water). This is a passive transportation which do not require the expense of energy from the cell.
In contrast, when molecules move in or out of the cell against their concentration gradient, that is ions moving from hypotonic region to hypertonic region, they implore the expense of energy in form of adenosine triphosphate (ATP), and the involvement of the membrane carrier proteins. This is called active transport.
Sound waves are both compressional and longitudinal, (although we frequently draw them as transverse waves).
Longitudinal waves are where the particles of matter collide into one another, pushing them into the next and then oscillating back. This is how sound travels. This is also why sound can only travel through a medium, it cannot travel through a vacuum, as is shown here: