Question

Which of the following statements about passive transport is true?

A. Passive transport refers only to the movement of water.
B. Energy input is required.
C. Substances move along their concentration gradients.
D. Membrane proteins are always needed.

Answer 1

Passive transport is the movement of substances along their concentration gradients from higher to lower concentration areas without the necessity for cellular energy (ATP).

Step-by-step explanation:

Substances move along their concentration gradients. Passive transport is a naturally occurring phenomenon that does not require the cell to use energy. It involves the movement of substances from areas of higher concentration to areas of lower concentration. This movement can occur through the lipid bilayer of the cell membrane or with the assistance of membrane proteins in a process known as facilitated transport.

However, these proteins do not require energy to function in passive transport. Passive transport is the movement of substances across a cell membrane without the input of energy. This type of transport occurs along the concentration gradient, with substances moving from an area of higher concentration to an area of lower concentration.