Which of the following molecular movements is due to diffusion or osmosis?

Question

When a plant cell is placed in concentrated salt water, water moves out of the cell.
The sodium-potassium pump pumps three sodium ions out of a neuron for every two potassium ions it pumps in.
Cells of the pancreas secrete insulin into the bloodstream.

Answer 1

The molecular movement that is due to diffusion or osmosis in the statements provided is:

When a plant cell is placed in concentrated salt water, water moves out of the cell.

This movement is a result of osmosis, which is the diffusion of water across a semipermeable membrane from an area of lower solute concentration (inside the plant cell) to an area of higher solute concentration (the concentrated salt water).

The other two statements describe active transport (the sodium-potassium pump) and secretion (cells of the pancreas secreting insulin) and are not primarily driven by diffusion or osmosis.