Diversity of organisms
Learning Objectives
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List the five kingdoms used to classify plant
and animals
Discuss the plant kingdom with the
flowering plant as an example
Discuss the animal kingdom with the human
as an example
Classification
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In order to organise information about the
wide variety of life on earth a system of
classification is required.
Taxonomy is the study of classification.
Classification
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Old systems of classification were based on
separating life into two categories: Animals
and Plants.
With developments in science came the
discovery of new forms of life
A more updated five kingdom system was
proposed. It has since gained widespread
acceptance by the scientific community.
Five kingdom system of
classification
Life on earth can be divided up into 5 Kingdoms
Monera
Protista
Fungi
Plantae
Animalia
Five kingdom system of
classification
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Each of the five kingdoms can be further
subdivided into smaller categories.
Each successive category contains organisms
that are more and more similar.
The final category into which organisms can
be placed is the species.
Members of the same species are capable of
interbreeding to produce fertile offspring.
Monera (Prokaryotae)
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This kingdom contains
about 10,000 identified
species of bacteria.
It is estimated that there
are many more.
Bacteria were the first
organisms on earth.
They are by far the most
numerous organism on
the planet.
Monera – main features
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They are mainly microscopic and single celled
organisms.
They do not have a membrane enclosed
nucleus.
They do have membrane enclosed organelles
such as mitochondria and chloroplasts.
They normally reproduce asexually.
Monera
Protista (Protoctista)
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Contains a wide variety
of organisms from large
plant-like algae
seaweeds to singlecelled organisms such
as Amoeba.
Protists are found
almost anywhere water
is present.
Protista – main features
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Contains single celled (Amoeba) and simple
multicellular organisms (Algae)
They have a membrane-enclosed nucleus
Some feed by taking in organic substances
(they absorb nutrients through the cell wall)
Others can produce their own food by
photosynthesis
Protista
Fungi
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Examples of fungi
include mushrooms,
mildews, moulds and
yeasts.
Fungi play a vital role in
that they break down
dead organisms and
allow minerals to be
recycled.
Fungi - main features
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They are mainly multicellular.
They are composed of threads called hyphae.
A Hypha consists of one or more cells
surrounded by a tubular cell wall.
Cell walls are made of a carbohydrate called
chitin.
They are unable to make their own food.
Their method of reproduction involves spores.
Fungi
Learning Check
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Why do we have a system of classification?
What is the study of classification called?
What are the main differences between
members of the first two kingdoms mentioned?
What are the 5 kingdoms called?
Plants
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This kingdom includes
the mosses, ferns and
seed-producing plants.
Seed producing plants
can be further subdivided into flowering
and non-flowering.
Plants – main features
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All plants are multicellular
Their cells have cell walls made of the carbohydrate
cellulose
Their cells often have large vacuoles
They are eukaryotic – the have a true nucleus and
membrane enclosed organelles).
Chloroplasts containing the pigment chlorophyll
which enables photosynthesis. All plants are
autotrophs.
They reproduce asexually and sexually.
Plants
Animals
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This kingdom includes
jellyfish, flatworms,
snails, roundworms,
segmented worms,
frogs, lizards, birds and
humans.
The first animals
evolved in the sea about
700 million years ago.
Animals – main features
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All organisms in this Kingdom are multicellular
They are eukaryotic - have a nucleus and
membrane enclosed organelles
Animal cells have no cell walls
All animals are heterotrophic – they cannot
produce their own food
They normally reproduce sexually.
Animals
Learning Check
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What are the main differences between plants
and animals with regard to cells?
What other features distinguish plants from
animals?
Syllabus
Can you answer the following
questions?
Depth of treatment
Name the Five kingdom system of classification:
 Monera (Prokaryotae)
 Pritista (Protoctista)
 Fungi
 Plant
 Animal
(Further sub-classification not required).