Essential nutrients move through a cell membrane by both passive transport and active transport. Which of the following correctly describes the transport of materials across a cell membrane?
a) Active transport requires chemical energy to move nutrients from areas of low concentration to areas of high concentration.
b) Passive transport requires chemical energy to move nutrients from areas of low concentration to areas of high concentration.
c) Active transport moves nutrients from areas of high concentration to areas of low concentration without the use of chemical energy.
d) Passive transport moves nutrients from areas of low concentration to areas of high concentration without the use of chemical energy.
