Question

Which of the following processes does cause substances to move across membranes without the expenditure of cellular energy?

• A. Endocytosis
• B. Exocytosis
• C. Active transport
• D. Diffusion or passive transport

Answer 1

The correct option is D

Diffusion or passive transport

The correct option is D:

Explanation of the correct option:

1. Passive transport like diffusion is the movement of a substance from a region of high concentration to a region of low concentration, i.e., along with the concentration gradient.
2. It does not require additional expenditure of cellular energy.

Explanation of the incorrect option:

Option A:

1. Endocytosis is the engulfment of food and other substances from an external medium by a plasma membrane.
2. Endo means inside and cyto means cell meaning it is inside the cell.
3. Amoeba takes their food through this process.

Option B:

1. Exocytosis is a form of active transport, in which a cell transports molecules out of the cell.
2. It is the process that involves the fusion of the membrane of the exocytotic vesicle with the plasma to extrude its contents to the surrounding medium.

Option C:

1. Active Transport is a process that involves the movement of molecules from a region of lower concentration to a region of higher concentration against an obstacle with the use of external energy in the form of ATP.
2. Glucose, amino acids, and some ions are absorbed by active transport.

Final answer: Diffusion or passive transport causes substances to move across membranes without the expenditure of cellular energy.