Question

A concentration gradient ceases to exist when?

1) All molecules have moved from low concentration to high concentration.
2) The membrane pores close.
3) The temperature drops.
4) There is equilibrium between the two sides of a membrane.
5) Bulk flow intervenes.

Answer 1

A concentration gradient ceases to exist when molecules have reached equilibrium or bulk flow interrupts the diffusion process. The correct option is 5) Bulk flow intervenes.

Step-by-step explanation:

Diffusion is the movement of molecules from an area of high concentration to an area of lower concentration. When there is no longer a concentration gradient, equilibrium is reached and the movement of molecules stops.

This can happen when all molecules have moved from a low concentration to a high concentration, or when there is an equal concentration of molecules on both sides of a membrane.

Bulk flow, on the other hand, involves the movement of molecules due to external forces and can disrupt the concentration gradient, ceasing the diffusion process. The correct option is 5) Bulk flow intervenes.