Classification
Learning Outcomes
To list and describe the
characteristics of living organisms
To define the terms nutrition,
excretion, respiration, sensitivity,
reproduction, growth and movement
Life Processes
Living organisms carry out all of the seven
life processes.
• Movement
• Respiration
• Sensitivity
• Growth
• Reproduction
• Excretion
• Nutrition
Characteristics of Living Things
M is for movement
• Animals move to find food, shelter or a mate.
• Plants do not move in the same way as animals but
move towards sunlight.
Characteristics of Living Things
R is for reproduction
• Animals lay eggs or have babies.
• Seeds from plants grow into new plants.
Characteristics
of Living Things
• S is for sensitivity.
• Eg: we hear, see and respond to touch
• Plants respond to gravity and light.
• All organisms pick up (detect/sense) information about the
changes in their environment and react to changes
G is for growth
Characteristics of Living Things
• Growth is an increase in size permanently
• Animals stop growing when they reach adult size.
• Plants grow throughout their lives.
R is for respiration
• Respiration is the release of energy from food.
• This usually needs oxygen.
E is for excretion
• All organisms produce unwanted or toxic waste products as result of their
metabolic reactions
• The removal of this waste is called excretion.
• Animals excrete through their lungs, kidneys and skin.
N is for nutrition
• All living things need food for energy, growth and repair.
• Animals have to find their own food and eat plants and other animals.
• Plants make their own food by the process of photosynthesis.
G is for growth
Characteristics of Living Things
• Growth is an increase in size permanently
• Animals stop growing when they reach adult size.
• Plants grow throughout their lives.
R is for respiration
• Respiration is the release of energy from food.
• This usually needs oxygen.
Characteristics of Living Things
E is for excretion
• All organisms produce unwanted or toxic waste products as result of their metabolic
reactions
• The removal of this waste is called excretion.
• Animals excrete through their lungs, kidneys and skin.
Characteristics of
Living Things
What is classification?
• There are a huge variety of organisms living on Earth.
• Throughout history, scientists have put living things into groups to
make them easier to identify.
• This is called classification.
• Organisms sharing particular features are put into the same group
Learning Objective
• To describe the impact of developments in biology on classification
systems.
Success Criteria
• To name organisms using the binomial system.
• To explain why the classification system has changed.
• To compare morphology to produce an evolutionary tree.
What Am I?
Photo courtesy of (@wikimedia.org) - granted under
creative commons licence – attribution
groundhog
woodchuck
whistle pig
marmot
grass rat
earth pig
Photo courtesy of (@wikimedia.org) - granted under
creative commons licence – attribution
firefly
lightening bug
glow fly
moon bug
golden sparkler
fire devil
blankie
big dipper
crayfish
crawdad
crawfish
mudpuppy
crawdad
freshwater lobster
mountain lobster
mudbug
What Am I?
Many species have lots of different names in common use.
Why might this be a problem?
Another problem is when two species share a common name.
These plants are both called hemlock.
Photo courtesy of Malcom Manners (@flickr.com) - granted under
creative commons licence – attribution
This one is a harmless conifer.
Photo courtesy of Paige Filler(@flickr.com) - granted under
creative commons licence – attribution
This one is poisonous.
Carl Linnaeus
Linnaeus recognised that there was a problem with naming living things.
Everybody argued about the names of plants and doctors often used
long complicated names.
How would he know which to prescribe for each ailment when some
could have 30 different names?
He came up with a simple system for naming every living thing that was
based on just two parts, given in Latin.
For example
a) the rose that he used to heal dog bites was named Rosa canina
b) Homo sapiens which means wise humans
Carl Linnaeus
The first part of the name that Linnaeus gave to each organism is the genus and
the second part is the species.
genus
Homo
species
sapiens
This is called the binomial system.
bi = two
nomial = name
Linnaeus chose to name organisms in Latin. It was no longer spoken and so
nobody was offended because their language wasn’t chosen.
• The binomial name is always written in italics.
• The genus starts with a capital letter.
• The species starts with a lowercase letter.
The Linnaean system
• Carl Linnaeus (1707-1778) was a Swedish scientist who classified
organisms into groups according to their structure and characteristics.
• Linnaeus classified all living things into a seven tier hierarchy:
Going down from kingdom to species,
there are fewer organisms within each group
However, the organisms in each group share
more and more common features.
The Linnaean system
Seven tier hierarchy:
• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species
After domains, the kingdom classification gets a bit
more specific.
For example, is it a plant or an animal?
• ANIMAL KINGDOM
• PLANT KINGDOM
• FUNGUS KINGDOM
The Linnaean system
• Seven tier hierarchy:
a) Kingdom
Kingdom Animal have 2 phyla
b) Phylum
- Chordata phylum which have
c) Class
a) a notochord
d) Order
b) a dorsal hollow nerve cord
e) Family
c) pharyngeal slits
f) Genus
d) a post-anal tail.
g) Species
-Arthropoda phylum (invertebrate animal with exoskeletons)
For example, all insects, spiders, and crustaceans belong to
this phylum.
The Linnaean system
• Seven tier hierarchy:
a) Kingdom
b) Phylum
For example, the Chordata phylum contains class mammals,
c) Class
reptiles, and amphibians.
d) Order
e) Family
f) Genus
g) Species
The Linnaean system
• Seven tier hierarchy:
a) Kingdom
b) Phylum
c) Class
d) Order
Family
e) Family
Share key features
f) Genus
(horse, donkeys and zebra grouped in the horse family)
g) Species
The Linnaean system
• Seven tier hierarchy:
a) Kingdom
b) Phylum
c) Class
d) Order
e) Family
Share many characteristics (eg: plain zebra & mountain zebra)
f) Genus
Share many features and can interbreed to produce
g) Species
fertile offspring
Carl Linnaeus
Linnaeus classified organisms into the following groups:
kingdom
animalia
animalia
plantae
phylum
chordata
chordata
magnoliophyta
class
mammalia
mammalia
magnoliopsida
order
primates
primates
asterales
family
hominidae
cercopithecidae
asteraceae
genus
Homo
Nasalis
Helianthus
species
sapiens
larvatus
annuus
What is a
species?
• A species is a group of organisms that can interbreed to produce
fertile offspring.
• Two organisms in the same species share many features in common
• However, there is variation within a species.
• This explains why individuals in the same species don’t all look the
same.
Make food by photosynthesis,
which takes place in
chloroplasts
Have a cellulose
cell wall
Cannot make their own food
Are often complex organisms
with a nervous system
Move from one place to another
in order to find food
Do not move from one place to
place
Make food by photosynthesis,
which takes place in
chloroplasts
Have a cellulose
cell wall
Do not move from one place to
place
Cannot make their own food
Are often complex organisms
with a nervous system
Move from one place to another
in order to find food
Methods of classification
• In the past, scientists used the physical features of organisms to
identify how similar they were and therefore decide how to classify
them.
• These features included
a) Morphology (the study of what organisms look like)
b) Anatomy (the study of the body structure of organisms)
• This works well when organisms share similar features because they
evolved from a shared ancestor.
• It fails when organisms share features that are adaptations to a
particular habitat
Developments in Biology
When Linnaeus started to classify organisms, he used the
morphology of the organism
Example:
Bats had teeth and gave birth to live young like mammals;
birds had beaks and laid eggs.
What developments have happened in biology since
the 18th century that might help us to better classify
organisms?
Developments in Biology
Microscopes allowed scientists to look at the
internal structure of cells.
• Sequencing the genomes of organisms allows scientists to see how
similar organisms are to each other.
• This gives them detailed information about the relationships
between organisms.
• Scientists are still sequencing new genomes now and this means
the classification system is still changing.
Changes to Classification
Scientists’ understanding of the biochemical makeup of cells has increased rapidly due to
the new developments.
This has meant new models of classification have been proposed.
Previously, there were five kingdoms, including one for prokaryotes. Microscope and
biochemical data showed that there were differences between some of these cells.
prokaryotes
Eukaryota cells are larger and
contain complex structures
including a nucleus. These are the
cells that make up animals, plants,
protists and fungi.
Bacterial cells are
smaller and have no
nucleus.
Archaea cells have
distinctive chemistry and
can survive extreme
environments.
Changes to Classification
In the Linnean system (1958), the largest group was the kingdom. But in the 1970s, Carl
Woese developed a new three-domain system. This had a higher classification above the
kingdom.
How many of these organisms can you correctly classify?
• Carl Woese proposed a three-domain system in 1990 after
advancements in chemical analysis techniques led him to discover
that some species weren’t as closely related as we originally thought.
• The three domains are:
a) Archaea– prokaryotic cells that live in extreme conditions.
b) Bacteria– true bacteria.
c) Eukaryota– broad range of organisms including plants, animals, fungi
and protists.
• Arachaea and bacteria often look very similar but they have lots
of biochemical differences.
• These domains are then split into the original groups
of kingdom, phylum, class, order, family, genus and species.
Evolutionary Trees
Evolutionary trees are models of how scientists think organisms are related.
They are built by looking at the similarities and differences between organisms.
The closer together the branches on a tree are, the more closely related the organisms are.
most recent common
ancestor of a & b
a
b
c
d
Species A is more closely related to species B than it is to
any of the other species.
Species A and B evolved from a common ancestor (the most
recent organism from which species A and B descended).
e
ancestors
present day species
Evolutionary Trees
gorilla
chimpanzee
orangutan
human
In the past, these similarities and
differences
morphology (the shape or
structure of an organism).
We used to think gorillas and
chimpanzees were the most
closely related of the great apes.
human
chimpanzee
gorilla
orangutan
Now, we can compare DNA
sequences and protein structures to
compare organisms.
This shows us that humans are
actually more closely related to
chimpanzees than the other great
apes are.
Evolutionary Trees
Use the morphological information that you have from the illustrations to
arrange the organisms into an evolutionary tree.
hippos
whales
ruminants
pigs
camels
horses
mesonychid
These relationships were
identified by comparing DNA
sequences. How close were
you based on morphology?
What Does the Tree Show?
dog
Give three bits of information
that the tree shows.
human
Examples:
elephant
mouse
armadillo
tammar wallaby
Give some organisms that are
closely related.
opossum
Which are the most distantly
related?
Give some organisms that share a
common ancestor.
Which species appeared most
recently?
platypus
chicken
tetrapods
lobe-finned fish
turkey
zebra finch
lizard
western clawed frog
chinese brown frog
lungfish
coelacanth
Binomial classifications
• Match the organism to its its binomial classification
Asian elephant
Felis catus
Human
Panthera tigris
Cat
Malus domestiga
Tiger
Elephas maximum
Apple
Homo sapiens
class
phylum
kingdom
species
genus
family
order
Level
of
classifications
• Put them into correct order
• Find the meaning of
a) Prokaryotes
b) Eukaryotes
c) Autotrophs
d) Heterotrophs
Terms
Keys
What is a kingdom?
• Originally, scientists tried to fit all organisms into just two kingdom:
plants and animals
• Today, we use a system that divides organisms into five kingdoms:
a) Animalia: all animals
b) Plantae: all plants
c) Fungi: all fungi
d) Protista: all protists
e) Prokaryote
Animal
Classifications
The animal kingdom
• Animal are usually easy to recognize.
• Most animals can move actively, looking
for food. Under the microscope, we can
see their cell have no cell walls.
• Characteristics
a) Their cells have nucleus, but no cell walls
or chloroplasts
b) They feed on organic substances made
by other living organisms.
The animal kingdom
• The animal kingdom can be divided into two large groups:
a) Invertebrates (have no backbone)
b) Vertebrates (no backbone)
• The vertebrate are placed in the phylum Chordata.
• This phylum includes five orders:
a) Mammals
b) Birds
c) Reptiles
d) Amphibians
e) Fish
There are five different ways
we can class animals...
1) Mammals
How can we tell an
animal is a mammal?
They give birth to live young...
They have hair or fur...
Mammal mothers feed their children with their own milk...
They are warm blooded...
2) Reptiles
How can we tell an
animal is a reptile?
They have scales, not fur...
They have dry skin...
They usually lay eggs...
They are cold blooded...
3) Birds
How can we tell an
animal is a bird?
They have feathers and wings...
They lay eggs...
They are warm blooded...
4) Amphibians
How do we know if an
animal is an amphibian?
They live on land and water...
They are cold blooded...
They lay eggs...
They have moist skin and webbed feet...
5) Fish
How do we know if
an animal is a fish?
They breathe under water using gills...
They have scales and fins...
They lay eggs...
They are cold blooded...
What types of
animals are
these?...
Classification of Plants
The plant kingdom
• Plants are multicellular organisms (made up of more than one cells –
usually thousands or millions of cells)
• Characteristic features of plants:
a) Their cells have a nucleus and cell walls made of cellulose
b) often contain chloroplasts.
c) They feed by photosynthesis (autotrophs)
d) They may have roots, stems and leaves
• It can be divided into flowering plants and non-flowering plants (ferns
and mosses)
Classification of flowering plants
Key features
• Multicellular organisms
• Cellulose cell walls and sap vacuoles
• Roots, stems and leaves
• Some cells contain chloroplasts
• Two groups
a) Monocotyledons
b) Dicotyledons
• The term cotyledon means “seed
leaf”
Monocotyledons and Dicotyledons
FEATURE
MONOCOTYLEDON
DICOTYLEDON
Leaf Shape
Long and narrow
Broad
Leaf veins
parallel
Branching
Cotyledons
(seed leaf)
one
Two
Grouping of
flower parts
In threes
In fives
The plant kingdom
• Liverworts do not have roots and
flowers.
• Suggest how you could show that a
liverwort belongs to the plant
kingdom.
Q&A
1) Describe one difference between plant and animal cells
2) Describe one other difference between plants and animals
3) A new organism has been discovered. Some of its cells contain
chloroplasts. Should the organism be classified as a plant or as
an animal? Explain your answer.
The fungus kingdom
• Some fungi (such as yeast) are single celled,
but most have a structure consisting of fine
thread known as hyphae
• These are made up of many cells joined end
to end
• Several hyphae together form a mycelium
• Many fungi can be seen without a
microscope
• The cells have cell walls, but there are not
made of cellulose
The fungus kingdom
• Their cells do not contain
chlorophyll, so they do not
carry out photosynthesis
• To obtain nutrients, they
secrete digestive enzymes
outside the cells onto living or
dead animals or plant
materials, and absorb the
digested nutrients
(saprotrophic nutrition)
• Many fungi are decomposers, breaking
down waste material from other
organisms and dead organisms.
• This helps to return nutrients to the soil
that other organisms can use for their
growth
The fungus kingdom
The fungus kingdom
• Fungi reproduce by forming spores.
• There are tiny groups of cells with a tough,
protective outer covering.
• They can be spread by the wind or animals
and grow to form a new fungus.
• Some fungi are harmful cause food decay or
disease.
• They may also use for obtaining penicillin.
The fungus kingdom
• Characteristics feature of fungi
a) They are usually multicellular (many-celled), but
some such as yeast are unicellular (single-celled)
b) They have nuclei (eukaryotes) and cell walls, but
the walls are not made of cellulose.
c) They do not have chlorophyll
d) They feed by digesting waste organic material and
absorbing it into their cells.
https://www.youtube.com/watch?v=5PWcEpAHjGE
The protoctists kingdom
• They all have cells with a nucleus, but some
have plant-cells with chloroplasts and
cellulose cell walls, while others have
animal-like cells without these features.
• Most protoctists are unicellular (made of
just a single cell) but some, such as
seaweeds, are multicellular.
• Eg:
a) Paramecium, Amoeba (animal-like cells)
b) Chlamydomonas (plant-like cells)
The protoctist kingdom
• Characteristics features of protoctists
a) They are multicellular or unicellular
b) Their cells have a nucleus (eukaryotes)
and may or may not have a cell wall and
chloroplasts
c) Some feed by photosynthesis and others
feed on organic substances made by other
organisms
The prokaryote kingdom
Pro – before
Karon – nucleus (Greek)
• Characteristics features of prokaryotes
a) They are usually unicellular (single-celled)
b) They have no nucleus
c) They have cell walls, not made of nucleus
d) They have a circular loop of DNA, which is
free in the cytoplasm
e) They have no mitochondria
f) They often have plasmids(additional
genetic materials).
Q&A
• Staphylococcus aereus is a bacterium that is often found on human skin.
a) Name the genus to which this bacterium belongs
b) Name the kingdom to which this bacterium belongs
c) Describe two ways in which the structure of Staphylococcus aereus
differs from the structure of plant cell.
https://www.youtube.com/watch?v=Xzy4Ze93G3g
Animalia
•
•
•
•
Characteristics:
Multicellular
Heterotrophic feeders:
no chlorophyll
No cell walls
Complex cell structure
with a nucleus
Plantae
•
•
•
•
Characteristics:
Multicellular
Autotrophic feeders: use
chlorophyll
Cell walls made of cellulose
Complex cell structure with a
nucleus
Fungi
•
•
•
•
Characteristics:
Multicellular
Cell walls not made of cellulose
Saprophytic feeders: no chlorophyll
Complex cell structure with a nucleus
Protoctista
Characteristics:
• Mostly unicellular (some are multicellular)
• Complex cell structure with a nucleus.
Prokaryotae
Characteristics:
• Unicellular
• Simple cell structure with no nucleus
The Five Kingdoms of
Living Organisms
Classification of Animals
Scientists have divided the Animal
Kingdom into two main groups:
vertebrates
(animals with a
backbone)
and
invertebrates
(animals without a
backbone)
Vertebrates
Animals with a backbone.
Vertebrates
Animals with backbones can be divided into five more groups:
Mammals
Birds
Amphibians
Reptiles
Fish
Mammals
• Give birth to live young.
• Feed their babies with
their own milk.
• Are more or less covered
with hair.
• Are warm-blooded.
Birds
• Have feathers.
• Lay eggs.
• Are warm-blooded.
Reptiles
• Are cold-blooded.
• Lay eggs.
• Have a dry skin covered
with scales.
Amphibians
• Are cold-blooded.
• Lay eggs.
• Have a smooth, moist skin.
• Are able to live on land as
well as in the water.
Fish
• Are cold-blooded.
• Lay eggs (but some do give
birth to live young).
• Have a moist skin covered
in scales.
• Breathe through gills.
Invertebrates
Animals without a backbone.
Classification of Invertebrates
• The main groups of invertebrates are
• Arthropods
• Annelids
• Nematodes
• Molluscs
• Echinoderms
Arthropods
• Special features
• They are invertebrates
• They have a waterproof exoskeleton
• Their bodies are segmented
• They have jointed limbs
• Four main classes of arthropod
• Insects
• Arachnids
• Crustaceans
• Myriapods
Arthropods - Insects
• Examples
• Dragon fly
• Locust
• Key features
• Three pairs of legs
• Two pairs of wings
• One pair antennae
• Compound eyes
• Body – head, thorax and abdomen
Arthropods - Arachnids
Examples
• Spider
• Tick
Key features
• Four pairs of legs
• Body divided into head and abdomen
• Several pairs simple eyes
• Chelicerae for biting / poisoning prey
Arthropods - Crustaceans
• Examples
• Crab
• Woodlouse
• Key features
• Five or more pairs of legs
• Two pairs of antennae
• Head and abdomen
• Exoskeleton forms a hard carapace
• Compound eyes
Arthropods - Myriapods
• Examples
• Centipede
• Millipede
• Key Features
• Ten or more pairs of
legs
• One pair of antennae
• Simple eyes
Annelids
• Example
• Earthworm
• Key Features
• Long, cylindrical body
covered with mucus
• Segmented body
• bristles
Nematodes
• Examples
• Ascaris
• Key features
• Long and cylindrical
body
• Body not
segmented
• Body pointed at
both ends
Molluscs
Examples
• Snail
Key features
• Most have a shell,
hardened by calcium
carbonate
• Have a muscular foot
• May have eyes on
tentacles
Protozoa
Microscopic and only seen under microscopes.
All reproduce asexually by splitting in half.
Annelids
These are ‘worm-like; creatures.
They include garden worms, flatworms and leeches.
Molluscs
These muscular feet and many have a shell.
They include snails, mussels and the octopus,
Echinoderms
These have bodies divided into 5 parts.
They include starfish and sea urchins.
Arthropod
These have a hard outer skeleton made of pieces, like a
suit of armour.
They include insects, spiders, crabs and centipedes.
What type of
invertebrate?
Our
evidence?
What type of
invertebrate?
Our
evidence?
What type of
invertebrate?
Our
evidence?
What type of
invertebrate?
Our
evidence?
What type of
invertebrate?
Our
evidence?
Groups of
animals
A quiz on vertebrates and invertebrates
Vertebrates
Q1. What are the five
groups of vertebrates
called?
Hint:
MR FAB
Vertebrates
Q2. What do vertebrates have in common?
Invertebrates
Q3. Name two groups of invertebrates
Vertebrates and
invertebrates
Q4
a. Name one of these animals in this group
b. Name the group these animals belong to
C. Give a reason for choosing this group
Vertebrates and
invertebrates
Q5.
a. Name one of these animals in this group
b. Name the group these animals belong
to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q6
a. Name one of these animals in this group
b. Name the group these animals belong to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q7
a. Name one of these animals in this group
b. Name the group these animals belong
to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q8
a. Name one of these animals in this group
b. Name the group these animals belong to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q9
a. Name one of these animals in this group
b. Name the group these animals belong to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q10
a. Name one of these animals in this group
b. Name the group these animals belong to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q11
a. Name one of these animals in this group
b. Name the group these animals belong to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q12
a. Name one of the animals in this group
b. Name the group these animals belong to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q13
a. Name one of the animals in this group
b. Name the group these animals belong to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q14
a. Name one of the animals in this group
b. Name the group these animals belong to
C. give a reason for choosing this group
Vertebrates and
invertebrates
Q15.
a. Name one of the animals in this group
b. Name the group these animals belong to
C. give a reason for choosing this group
Q16. Which is the odd one out and why?
A
B
turtle
walrus
hummingbird
C
lobster
D
Q17. Which is the odd one out and why?
frog
A
toad
gecko
C
D
salamander
B
Q18. Which is the odd one out and why?
A
B
SQUID
seahorse
C
shark
D
whale
End of topic question (Classification)
1.Name and describe the seven processes of life (7m)
2.Name a life process necessary for an organism to release energy.
[1m]
3.When you place a crystal of copper (II) sulfate in a saturated
solution of the same compound, the crystal will increase in size.
Does this mean that the crystal is alive? Explain your answer. [2m]
4.The binomial name of the lion is Panthera leo.
a) Which part of the name is unique to the lion? [1m]
b) What does the other part of name indicate? [1m]
5.Plants cannot move about, as animals can. Does that mean
animals are more alive than plants? Explain your answer. [2m]
End of topic question (Classification)
6. A zoo has a male animal and a female animal that look very alike.
They put them in the same enclosure to see if they will breed.
a) Suggest why the zoo think that the animals may be of the
same species. [1m]
b) Describe what the zoo would expect to happen if the animals
were of the same species. [1m]
c) Describe another method that the zoo could use to check if
the animals were of the same species. Explain your answer.
[2m]
7. Separate the following animals into two groups based on a main
features. [2m]
crab
dog
shark
bee
End of topic question (Classification)
8. Some people think viruses are living organisms, other people do
not.
a) Which characteristics of living organisms do viruses have? [1m]
b) List the characteristics of living organisms that viruses cannot do.
[2m]
9. Fungi were once classified as plants.
a) Suggest which features were used to justify this classification.
Explain your choices [2m]
b) Explain why fungi are no longer classified in the same kingdom as
plant. [2m]