Answer: Active Transport
Active and passive transport are two biological processes which are occurring all the time in the cells and body. These processes provide oxygen and other nutrients to the cells and remove waste materials from the body. But both processes differ from each other on the basis of gradient and expense of energy.
Because In active transport, nutrients move from low concentrated region to high concentrated region on the expense of energy whereas, in passive transport, nutrients move from high concentration to low concentration without the use of energy.
ACTIVE TRANSPORT, molecules move against the concentration gradient.
