What Are The Characteristics Of Life – Definition With Examples

What Are The Characteristics Of Life – Definition With Examples

Science of life is biology, but what is the definition of life? Defining life can be a challenge, even if it seems obvious. In Virology, researchers study viruses, which resemble living entities in some respects but lack in others.

Biologists define life as meeting the criteria that include being able to cause disease, reproduce, and attack living organisms. A virologist, therefore, is not a biologist. Scientists who study the early molecular evolution of life are also excluded from biology strictly speaking since these events are not biological events.

Throughout its history, biology has grappled with these questions: What makes something ‘live’? Then, how can we determine whether something is alive by finding meaningful levels of organization within its structure?

8 characteristics of life
8 characteristics of life

Life’s Characteristics

The functions of all living organisms include reproducing, growing, and developing, regulating, maintaining homeostasis, and processing energy. Considering these characteristics individually, it can be argued that life is what we experience.


A cell is a structure that consists of several cells that are highly organized and coordinated. An organism as simple as a single-celled animal can be surprisingly complex, as atoms inside the cell combine to form molecules, which then combine to form organelles and other components of the cell.

A tissue is formed by similar cells that are found in multicellular organisms. To summarize, tissues are composed of cells that work together to create organs (bodily structures that perform specific functions). Organ systems are formed as a result of organs working together.

Stimulus Sensitivity

Diverse stimuli are received by different organisms. Plants are capable of bending towards new sources of light, climbing onto walls or fences, even responding to touch as a response to touch.

Photographs of the Mimosa pudica showed it had many tiny leaves on a single stem connected to many tiny leaves. There are three stems that interlink together.

Chemotaxis is the movement of bacteria in response to chemicals and light.. Positive responses are believed to be brought about by movement toward a stimulus, while negative responses are believed to be brought about by movement away from a stimulus.

Reproduction In Living Organisms

A single-celled organism reproduces by first replicating its DNA, and then dividing that DNA evenly as it prepares to divide into two by dividing its cell wall in half. Many multicellular organisms produce genetic material that also serves as the basis for the development of new individuals.

It is important to know that containing DNA in genes, when an organism reproduces, those genes are passed on to the offspring. Genes that are present in these offspring assure that their offspring will be of the same species, as well as possess similar characteristics, such as size and shape.

Growth And Development In Living Organisms

A specific set of instructions are encoded in each gene of an organism to guide its growth and development.

The genes responsible for this type of regulation provide instructions on how to direct cellular growth and development, which means that offspring of a species will inherit many of their parents’ characteristics.


Despite their relatively small size, even the smallest creatures contain innumerable regulatory mechanisms to communicate with each other, coordinate internal functions, respond to triggers, and cope with environmental stresses.

The transport of nutrients and blood are two examples of internal processes that are controlled within an organism. There are many different kinds of organs (groups of tissues that work together) within the body, each with a specific function. These functions include carrying oxygen across the body, eliminating waste, delivering nutrients to all cells, and cooling the body.

Homeostasis In Living Things

In order for cells to function properly, they require the right temperature, pH level, and chemical concentration. At any moment, these conditions can change based on the changes happening in the surrounding environment.

It is said that organisms live within a narrow range of constant internal conditions, despite their environment changes, through a process known as homeostasis (“steady state”). It means the organism exists in a constant internal condition, despite environmental changes.

The process of thermoregulation is, for example, a method through which an organism regulates its body temperature. A polar bear, for example, has body structures that help it resist low temperatures while preserving body heat.

Polar bears live in extremely cold climates, and their body structure helps them endure low temperatures and conserve heat. The fur, feathers, blubber, and fat lining of the animal’s body are structures that aid in the insulation process.

As a consequence of hot climates, organisms have developed methods of shedding excess body heat that help shed excess heat (such as perspiration in humans and panting in dogs).

Energy Processing In Living Organisms

For organisms to perform their metabolic functions, they use an energy source. In some organisms, the sun’s energy is captured by the cells and is converted into chemical energy in the food they ingest (photosynthesis); in others, the energy is taken up by the cells in the form of molecules they take in as food (cellular respiration).

Living Things Are Organized At Various Levels

Organisms follow hierarchies that can be compared between small and large. At the fundamental level, an atom is the smallest element. A nucleus and electrons surround it. Atoms form molecules.

Molecules are chemical structures containing two or more atoms joined by chemical bonds. In biology, polymers are commonly formed from macromolecules, long molecules, i.e., large molecules that are formed through the combination of monomers that are simpler than macromolecules. Macromolecules include deoxyribonucleic acid (DNA), which instructs all living organisms on how to function.

Final Words:

Tissues, or groups of cells with similar functions, are found in larger organisms. Tissues perform a common function in larger organisms. Plants and animals both possess organs. An organ system refers to the organization’s higher levels, which have associated functions.

Humans have many organ systems. The circulatory system carries blood from the heart and lungs, as well as lungs through the body. An organism is an individual living thing. An organism can be a tree. In addition to prokaryotes and eukaryotes, there are also single-celled organisms, often referred to as microorganisms.

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