Which of the following is considered the most defining property of living organisms?

Which of the following is considered the most defining property of living organisms?

A. Growth
B. Reproduction
C. Metabolism
D. Movement

Correct Answer: C. Metabolism

Explanation:
Metabolism refers to the sum total of all chemical reactions that take place within a living organism. It includes processes such as anabolism and catabolism, which are essential for maintaining life.

According to NCERT, all living organisms are made up of chemicals and continuously perform metabolic reactions. This makes metabolism one of the most defining characteristics of living organisms.

Growth, reproduction and movement are also important characteristics of living organisms, but they cannot be considered universally defining properties. For example, non-living objects can also show growth by accumulation of material, and reproduction is not observed in all individual living organisms.

Why is this important for NEET?

NEET frequently tests the difference between defining characteristics and general characteristics of living organisms. Remember:

Metabolism → Defining characteristic of life ✅
Reproduction → Not an all-inclusive defining characteristic ❌
Growth → Not a defining characteristic by itself ❌

NCERT Key Point: Metabolic reactions can be demonstrated outside the body in cell-free systems, but these reactions alone are not considered living.