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Cambridge (CIE) IGCSE Biology Your notes
Characteristics, Classification & Features of
Organisms
Contents
Characteristics of Living Organisms
Concept & Uses of Classification Systems
Concept & Uses of Classification Systems Continued
Features of Organisms
Features of Organisms Continued
Page 1 of 25
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Characteristics of Living Organisms
Your notes
Characteristics of Living Organisms
Movement: an action by an organism or part of an organism causing a change of position or place
Respiration: the chemical reactions that break down nutrient molecules in living cells to release energy
for metabolism
Sensitivity: the ability to detect or sense stimuli in the internal or external environment and to make
appropriate responses
Growth: a permanent increase in size and dry mass by an increase in cell number or cell size or both
Reproduction: the processes that make more of the same kind of organism
Excretion: the removal from organisms of toxic materials, the waste products of metabolism (chemical
reactions in cells including respiration) and substances in excess of requirements
Nutrition: the taking in of materials for energy, growth and development; plants require light, carbon
dioxide, water and ions; animals need organic compounds, ions and usually need water
Examiner Tips and Tricks
Use this mnemonic to help you remember these processes:
MRS. GREN
Movement
Respiration
Sensitivity
Growth and development
Reproduction
Excretion
Nutrition
Page 2 of 25
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Concept & Uses of Classification Systems
Your notes
How Organisms are Classified
There are millions of species of organisms on Earth
A species is defined as a group of organisms that can reproduce to produce fertile offspring
These species can be classified into groups by the features that they share e.g. all mammals have
bodies covered in hair, feed young from mammary glands and have external ears (pinnas)
The Binomial System
Organisms were first classified by a Swedish naturalist called Linnaeus in a way that allows the
subdivision of living organisms into smaller and more specialised groups
The species in these groups have more and more features in common the more subdivided they get
He named organisms in Latin using the binomial system where the scientific name of an organism is
made up of two parts starting with the genus (always given a capital letter) and followed by the
species (starting with a lower case letter)
When typed binomial names are always in italics (which indicates they are Latin) e.g. Homo sapiens
The sequence of classification is: Kingdom, Phylum, Class, Order, Family, Genus, Species
Page 3 of 25
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Cambridge (CIE) IGCSE Biology Your notes
Characteristics, Classification & Features of
Organisms
Contents
Characteristics of Living Organisms
Concept & Uses of Classification Systems
Concept & Uses of Classification Systems Continued
Features of Organisms
Features of Organisms Continued
Page 1 of 25
© 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers
, Head to www.savemyexams.com for more awesome resources
Characteristics of Living Organisms
Your notes
Characteristics of Living Organisms
Movement: an action by an organism or part of an organism causing a change of position or place
Respiration: the chemical reactions that break down nutrient molecules in living cells to release energy
for metabolism
Sensitivity: the ability to detect or sense stimuli in the internal or external environment and to make
appropriate responses
Growth: a permanent increase in size and dry mass by an increase in cell number or cell size or both
Reproduction: the processes that make more of the same kind of organism
Excretion: the removal from organisms of toxic materials, the waste products of metabolism (chemical
reactions in cells including respiration) and substances in excess of requirements
Nutrition: the taking in of materials for energy, growth and development; plants require light, carbon
dioxide, water and ions; animals need organic compounds, ions and usually need water
Examiner Tips and Tricks
Use this mnemonic to help you remember these processes:
MRS. GREN
Movement
Respiration
Sensitivity
Growth and development
Reproduction
Excretion
Nutrition
Page 2 of 25
© 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers
, Head to www.savemyexams.com for more awesome resources
Concept & Uses of Classification Systems
Your notes
How Organisms are Classified
There are millions of species of organisms on Earth
A species is defined as a group of organisms that can reproduce to produce fertile offspring
These species can be classified into groups by the features that they share e.g. all mammals have
bodies covered in hair, feed young from mammary glands and have external ears (pinnas)
The Binomial System
Organisms were first classified by a Swedish naturalist called Linnaeus in a way that allows the
subdivision of living organisms into smaller and more specialised groups
The species in these groups have more and more features in common the more subdivided they get
He named organisms in Latin using the binomial system where the scientific name of an organism is
made up of two parts starting with the genus (always given a capital letter) and followed by the
species (starting with a lower case letter)
When typed binomial names are always in italics (which indicates they are Latin) e.g. Homo sapiens
The sequence of classification is: Kingdom, Phylum, Class, Order, Family, Genus, Species
Page 3 of 25
© 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers
