Question

The movement of molecules in the image given below is by

• A. diffusion
• B. facilitated diffusion
• C. active transport
• D. both diffusion and active transport

Answer 1

The correct option is B facilitated diffusion

From the given images, it is clear that molecules are moving from a region of higher concentration to lower concentration across the membrane. Hence it can be diffusion or facilitated diffusion. In active transport, molecules move from a region of lower concentration to higher concentration.
The image is of facilitated diffusion as the molecules are being transported by proteins. These are called carrier proteins. The carrier proteins bind to the molecule that needs to be transported and undergo changes to transport the molecule to the other side of the membrane.
In simple diffusion, the molecules move across the membrane without the help of transport proteins.