Question

Movement of materials against concentration gradient is achieved by
A. Active transport
B. Passive transport
C. Diffusion
D. Osmosis

Answer 1

Hint: In the living cells, different types of materials move to the inside as well as outside. The movement of the different substances are required as the cells require several different varieties of ions, and molecules to perform various biological purposes.

Complete answer:
The cells are enclosed in a thin semipermeable membrane which allows passage of some of the substances quite freely while others are restricted or may be allowed on the basis of certain conditions. The movement of materials or substances are essential to maintain a steady flow of nutrients and other useful materials and also the waste materials are removed from the external environment.
The movement of material inside or outside the partially permeable cell membrane is dependent on the concentration gradient. When a substance or material moves against the concentration gradient, the process requires energy. This process is known as active transport. In the process of active transport, the material moving inside or outside is pushed against the concentration gradient which means movement takes place from an area of lower concentration to an area of higher concentration. It transports needed energy and is facilitated by the expenditure of ATP.
Passive transport is the movement of substances from the area of higher concentration to the area of lower concentration and it does not require energy for the process. It is a spontaneous process.
The substances when moved from an area of higher concentration to lower concentration and they move along the concentration gradient are known as diffusion of materials. In this process, materials will diffuse upon rates of diffusion according to their concentration gradient. It is a type of passive transport.
The process of osmosis is the movement of water across a membrane from the area of low solute concentration to an area of higher solute concentration. Osmosis occurs due to the differences in the concentration of solute.
Thus, the right option is A.

Note: The process of movement of materials or substances occurs across the semipermeable membrane. The movement of materials when it takes place against the concentration gradient is known as active transport. It requires the use of energy in the form of ATP.