# Wikijunior:Biology/Life



## Definition of Life

Scientists have come up with over a hundred different definitions of the
term \"life\". Many definitions are similar. They usually belong to one

## Definitions

-   **Enumeration of properties**\
    *Life is a system that has a metabolism, can grow, multiply and move

Definitions should help to avoid misunderstandings when working
together. Scientists have therefore developed quality criteria for
definitions.

With enumerations, a problem arises with classification if not all
criteria are met. Enumerated definitions are of low quality.

Metabolism wip.png\|thumb\|Metabolism Cross-section of an Oak Log
Showing Growth Rings.jpg\|thumb\|Growth Rings Sonchus April
2010-1.jpg\|Seeds Christie (racing automobile)
LCCN2014682300.jpg\|thumb\|Racing Automobile Darwin Hybrid Tulip
Mutation 2014-05-01.jpg\|Tulip with Mutation

-   **Matter and Energy**\
    *Life is a system of nucleic acids and polymerases that absorbs and

The definition is limited. It relates to earthly life.

Some scientists suspect that there are life forms in space that use
other substances.

RNA Polymerase II.png\|thumb\|RNA Polymerase

-   **Information**\
    *Life is a system that can absorb, process and deliver information

The definition is wide. It does not separate biology from technology.\

Papertape3.jpg\|thumb\|Information

-   **Themodynamics**\
    *Life is an unstable system that creates and maintains order within

This definition applies to other aspects of life: Living beings try to
maintain order so they don\'t die.

That\'s true, but definitions are meant to be intuitive.\

Mischentropie.jpg\|thumb\|Entropie

The definitions listed distinguish between animate and inanimate.

In the following symbiosis-based definition, there is a graded
transition. Organisms are a higher life form than unicellular organisms
because they rely on more symbioses.

-   **Scientifically - philosophically**\
    *Life is based on symbioses, ie on cooperation for mutual benefit.
    Philosophical: Life is based on the principle of love.*

Principle-based definitions are of higher quality than adhock
definitions.

This is a principle-based definition: symbioses form the basis of life.
But biologists have different opinions on this question.

The symbiosis definition gives life an (ethical) value, which is
important for doctors and lawyers. But many biologists strictly reject
the use of philosophical terms like \"love\".\

Common clownfish curves dnsmpl.jpg\|thumb\|Clownfish with Sea anemone
African buffalo (Syncerus caffer caffer) male with cattle
egret.jpg\|thumb\|African buffalo with cattle egret Hummingbird hawkmoth
a.jpg\|thumb\|Hummingbird with Plant
PloverCrocodileSymbiosis.jpg\|thumb\|Crocodile with Plover Lasius niger
y Cinara tujafilina en Thuja orientalis.jpg\|thumb\|Ant with Aphid
Lichen Cladonia portentosa and Hypogymnia physodes.jpg\|thumb\|Lichen:
Mushroom with Algae

Life is diverse. Each of these definitions illuminates different aspects
of life.




`== Literature ==`



[^1]: 

[^2]: 

[^3]: 

[^4]: 

[^5]: 

[^6]: 
