CIE IGCSE Biology Revision Notes savemyexams.co.uk
CHARACTERISTICS
2 ORGANISATION
& CLASSIFICATION
OF THE ORGANISM
OF LIVING ORGANISMS
YOUR NOTES
CONTENTS:
1.1 CHARACTERISTICS
1.2 CLASSIFICATION
1.3 FEATURES OF ORGANISMS
1.4 CLASSIFYING ANIMALS
1.5 CLASSIFYING PLANTS (EXTENDED ONLY)
1.6 VIRUSES (EXTENDED ONLY)
1.7 DICHOTOMOUS KEYS
VIEW EXAM QUESTIONS
1.1 CHARACTERISTICS
Characteristics of Living Organisms: Basics
• Movement: an action by an organism causing a change of position or place
• Respiration: the chemical reactions that break down nutrient molecules in living cells to
release energy
• Sensitivity: the ability to detect and respond to changes in the environment
• Growth: a permanent increase in size
• Reproduction: the processes that make more of the same kind of organism
• Excretion: the removal from organisms of toxic materials and substances in excess of
requirements
• Nutrition: the taking in of materials for energy, growth and development
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REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
CHARACTERISTICS & CLASSIFICATION OF LIVING ORGANISMS
YOUR NOTES
1.1 CHARACTERISTICS cont...
EXTENDED ONLY
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
EXAM TIP
Use this mnemonic to help you remember these processes:
MRS. H. GREN
Movement Respiration Sensitivity
Homeostasis
Growth and development Reproduction Excretion Nutrition
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REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
CHARACTERISTICS
2 ORGANISATION
& CLASSIFICATION
OF THE ORGANISM
OF LIVING ORGANISMS
YOUR NOTES
1.2 CLASSIFICATION
How Organisms are Classified: Basics
• 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
Linnaeus’s system of classification
CIE IGCSE Biology Resources
© copyright Save My Exams Page 3
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
CHARACTERISTICS
2 ORGANISATION
& CLASSIFICATION
OF THE ORGANISM
OF LIVING ORGANISMS
YOUR NOTES
CONTENTS:
1.1 CHARACTERISTICS
1.2 CLASSIFICATION
1.3 FEATURES OF ORGANISMS
1.4 CLASSIFYING ANIMALS
1.5 CLASSIFYING PLANTS (EXTENDED ONLY)
1.6 VIRUSES (EXTENDED ONLY)
1.7 DICHOTOMOUS KEYS
VIEW EXAM QUESTIONS
1.1 CHARACTERISTICS
Characteristics of Living Organisms: Basics
• Movement: an action by an organism causing a change of position or place
• Respiration: the chemical reactions that break down nutrient molecules in living cells to
release energy
• Sensitivity: the ability to detect and respond to changes in the environment
• Growth: a permanent increase in size
• Reproduction: the processes that make more of the same kind of organism
• Excretion: the removal from organisms of toxic materials and substances in excess of
requirements
• Nutrition: the taking in of materials for energy, growth and development
CIE IGCSE Biology Resources
© copyright Save My Exams Page 1
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
CHARACTERISTICS & CLASSIFICATION OF LIVING ORGANISMS
YOUR NOTES
1.1 CHARACTERISTICS cont...
EXTENDED ONLY
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
EXAM TIP
Use this mnemonic to help you remember these processes:
MRS. H. GREN
Movement Respiration Sensitivity
Homeostasis
Growth and development Reproduction Excretion Nutrition
CIE IGCSE Biology Resources
© copyright Save My Exams Page 2
REVISION NOTES TOPIC QUESTIONS PAST PAPERS
, CIE IGCSE Biology Revision Notes savemyexams.co.uk
CHARACTERISTICS
2 ORGANISATION
& CLASSIFICATION
OF THE ORGANISM
OF LIVING ORGANISMS
YOUR NOTES
1.2 CLASSIFICATION
How Organisms are Classified: Basics
• 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
Linnaeus’s system of classification
CIE IGCSE Biology Resources
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REVISION NOTES TOPIC QUESTIONS PAST PAPERS
