Living organisms: Definition and characteristics


Living organisms have various characteristics that aid in their recognition and differentiation from non-living objects.  some important characters which we observe in living organisms are Growth, Reproduction, Sensitivity. there are also characters such as metabolic reactions, self-replication, self-organization, etc which are taking place inside living organisms. so we will discuss whether these are the real defining characters of living organisms or can we take them as the Exclusive characters of living organisms.


All biological entities have the ability to grow. Growth is the unstoppable rise in the number of cells and mass that occurs inside the bodies of living creatures. Non-living objects, on the other hand, grow. Growth is not a defining characteristic of living entities.

Plant showing Growth


Living organisms have a basic ability to reproduce. It can be characterized as a grown-up individual producing new creatures of the same species. Some individuals, such as worker bees, mules, infertile human couples, and others, do not reproduce because they are sterile or infertile, and hence are unable to have offspring, but they exhibit all other characteristics of living beings. . As a result, reproduction isn’t a defining characteristic of living creatures.


To sustain its living state, a living cell undergoes several reactions during diverse processes such as photosynthesis, respiration, and so on. Metabolism refers to any reaction that takes place within a live cell. Non-living objects, on the other hand, do not display any reaction, i.e. metabolism.

Response to stimuli

Living creatures, such as microbes, plants, and animals, may detect a variety of changes. The human person is the only organism that is aware of itself, even if we are reading a book and someone walks by, we can still recognize movement. Non-living objects, on the other hand, are completely unaware of their surroundings. As a result, we might claim that all species, past, present, and future, are linked to one another to varying degrees through the sharing of genetic material.

Healing and Repair

Living creatures have the ability to repair and cure damaged or broken portions.


Death is the stoppage of various living activities accompanied by an increase in entropy. It might happen as a result of ageing, sickness, an accident, or predation.

Points to remember

*A situation of Degrowth or Negative Growth occurs when there is less Anabolism and more Catabolism in the living system

*Types of Growth

1. Indeterminate (unlimited) growth: Growth that continues throughout life.

2. Limited growth (determinate growth): Growth that happens only till a given age.

Multiple-choice questions (MCQs) and Practice tests (Living)

Question 1. What distinguishes living organisms from non-living organisms?

A.Growth, Reproduction, and Cellular organization

B. The ability to perceive and respond to environmental changes.

C.Ability to self-replicate, interact and emergence and movement, adaptation, variation, homeostasis, and life-span.

D.All of these.

Question 2. In plants Growth is




D.Both a and b

Question 3. Non-living objects like sand mounds, mountains, and boulders grow by

A.Cell Division

B.Accumulation of material on the surface


D.both b and c

Question 4. Unicellular and multicellular organisms grow by

A.Cell division



D.All of these

Question 5. The most evident and technically challenging aspect of all living organisms is


B.Cellular organisms


D.All of these.

Answers (key)


Leave a Comment

Your email address will not be published. Required fields are marked *