Question

Many molecules can move briefly across the membrane without any requirement of energy and special membrane proteins. This is called ________
A. Active Transport
B. Passive Transport
C. Facilitated diffusion
D. All of these

Answer 1

Hint: The practice of moving or distributing various resources or items from one location to another is known as transportation. Humans, in general, use a variety of modes of transportation. Similarly, the living system, which includes plants, animals, and humans, has an incredible transportation system that transports food, minerals, hormones, oxygen, carbon dioxide, waste products, and other essentials.

Complete explanation:
Option A: Active transport is described as “the transfer of molecules from an area of lower concentration to a region of greater concentration using external energy against a gradient or an obstacle.” A protein pump uses stored energy in the form of ATP to move molecules during the active transport phase.
So, option A is incorrect.
Option B: Passive transport is a type of membrane transport in which chemicals are moved across cell membranes without the need of energy. Passive transport uses the second law of thermodynamics to drive the movement of substances across cell membranes rather than cellular energy, as active transport does.
So, option B is correct.
Option C: The process of spontaneous passive movement of molecules or ions across a biological membrane via certain transmembrane integral proteins is known as facilitated diffusion.
So, option C is incorrect.
Option D: The movement of molecules across a membrane without the use of energy or a particular membrane protein to aid the movement is known as passive transport.
So, option D is incorrect.

Hence, Option B is the correct answer.

Note:
The fundamental movement of ions and other chemical compounds within cells along a concentration gradient without the need of external energy is known as passive transport. Passive diffusion is another name for it. Passive transportation can be divided into four categories: Diffusion, Filtration, Osmosis and facilitated Diffusion. The transfer of chemicals from a location of higher concentration to an area of lower concentration is known as diffusion.