Defining Properties of Living Organisms
A concise summary distinguishing between the defining and non-defining characteristics that truly differentiate living from non-living entities.
What is Defining Properties of Living Organisms?
The sum of all chemical reactions that occur within a living organism in order to maintain life.
Key points
- Differentiate between defining and non-defining characteristics of living organisms.
- Identify metabolism and cellular organization as universal defining properties.
- Understand why growth and reproduction are not always definitive.
- Appreciate the complexity in defining life.
Common exam trap
Confusing growth by accretion with biological growth.
Definitions
- Term
Metabolism
- Meaning
The sum of all chemical reactions that occur within a living organism in order to maintain life.
- Term
Growth
- Meaning
An irreversible increase in size, mass, or number of cells, characteristic of living organisms, but can also occur in non-living things by accretion.
- Term
Reproduction
- Meaning
The biological process by which new individual organisms – 'offspring' – are produced from their 'parents'.
- Term
Responsiveness
- Meaning
The ability of an organism to react to changes in its internal or external environment.
- Term
Cellular Organization
- Meaning
The characteristic of living organisms being composed of one or more cells, which are the fundamental units of life.
Learning objectives
Differentiate between defining and non-defining characteristics of living organisms.
Identify metabolism and cellular organization as universal defining properties.
Understand why growth and reproduction are not always definitive.
Appreciate the complexity in defining life.
Prerequisites
Basic understanding of biological terms.
Familiarity with different forms of life.
Common mistakes
Confusing growth by accretion with biological growth.
Assuming reproduction is a universal characteristic of all living individuals.
Overlooking metabolism as a key defining property.
Not recognizing cellular organization as the most fundamental characteristic.
Keywords
Living organisms
Non-living
Defining characteristics
Growth
Reproduction
Metabolism
Responsiveness
Cellular organization
Consciousness
Practice preview
All living organisms exhibit which of the following characteristics?…
easy
Which of the following statements about the characteristics of living beings is INCORRECT?…
medium
Which of the following is NOT a defining property of living organisms?…
easy