Replacement of Needed Salt or Disposal of Excess Salt Against

Question

Replacement of needed salt or disposal of excess salt against the gradient requires
A)facilitated diffusion.
B)active transport.
C)a kidney system.
D)impervious membranes,usually covered with mucus.
E)a hydrogen ion pump.

Accepted Answer

The process of replacing needed salt or disposing of excess salt against the gradient requires active transport. Active transport requires energy and moves substances from an area of lower concentration to an area of higher concentration, which is necessary for the movement of salt against the gradient. Facilitated diffusion moves substances from an area of higher concentration to an area of lower concentration without the need for energy. A kidney system is involved in regulating the balance of salt and water in the body but does not actively transport salt against the gradient. Impervious membranes, usually covered in mucus, help to prevent the loss of water, but they do not actively transport salt. A hydrogen ion pump is involved in generating an electrochemical gradient but is not directly involved in the transport of salt.