Living organisms are arranged in
different groups due to their
similarities and differences. This
grouping is called CLASSIFICATION.
Classification means to put things
intogroups according to
Binomial nomenclature is a formal system of
naming species of living things by giving
each a name composed of two parts, both of
which use Latin grammatical forms, although
they can be based on words from other
languages. Such a name is called a binomial
name (which may be shortened to just
"binomial"), a binomen or a scientific name;
more informally it is also called a Latin name.
Each species has two names. These are used
together to give a precise reference to this
Genus is given first and is always written with
an upper case letter. e.g. Homo
Species follows the genus and is written in
lower case e.g. sapiens
Therefore the species name for humans
is Homo sapiens
There are many different types of animals in
the world. Many animals are quite similar to
each other. Others are quite different.
without a Backbone
or Spinal Column
with a Backbone
or Spinal Column
No body layers rather there is an aggregate of
different cell types.
Support is from either silica or calcium based
spicules which link together to provide some
Body plan is built around water canals that
circulate nutrient through the sponge for
ingestion by specialised cells.
There is no mouth or anus
These have 2 layers in the body
Jelly fish are mobile organisms. Sea
anemones are sessile organisms.
These organisms are posses stinging cells
with toxins called nematocysts to disable
3 layers in the body plan.
One entrance to 'gut' which can have many
folds to increase surface area.
largely parasitic includes flukes
3 layers to the body plan / bilateral symmetry
body divided into ringed segments with some
specialization of segments
Mouth connected via gut to a separate anus.
Skin surface used for gas exchange.
Many marine forms but also terrestrial
species usually soil burrowing
Body plan has three major features:
Foot, a muscular structure used for
movement and burrowing.
Central visceral mass containing all the organ
structures (separate mouth and anus)
Mantle a folded membrane structure that can
surround other tissues and create a cavity
containing a gill.
The mantle frequently secretes a calcareous
Hard exoskeleton composed of chitin.
Jointed body segments.
Some flying organisms in the class Insecta. (
Separate mouth and anus.
Each question divides the group of organisms into
two smaller groups based on a pair of alternative
Subsequent groups may focus on more minor detail
In most cases the characteristic will be readily
observed or measurable
It is better to choose characteristics that are not
influenced by the environment
Shape and number are often good characteristics on
which to base alternative pairings of questions
A complete key will have each type of organism
classified separated along with a final identifying
Examples: earthworms, leeches, polychetes
• Ventral nerve cord
• Two types of muscles - longitudinal &
• Full utilization of coelom in
Water vascular system - system unique to
◦ Functions in
movement, support, respiration, digestion
Decentralized nervous system
Secondary radial symmetry
◦ Larvae are bilaterally symmetrical
◦ Adults are radially symmetrical
Waterproof skin covered in scales
Ectothermic, cold blooded
Hard shelled eggs that are waterproof
Reptiles are mainly or partially carnivorous
though there are some herbivorous species.
1) They are aquatic vertebrates that live in water.
They have representation both in fresh waters
and in marine waters and are also represented in
2) Their body is invariably stream lined and they
swim with the help of tail.
3) They have paired appendages in the form of
fins. Unpaired fins are also present. Fins help in
balancing during swimming.
This system of classification looks more
scientific and natural because of the following
Separation of prokaryotes into an
independent kingdom is justifiable because
they differ from all other organisms in their
Grouping of all unicellular eukaryotes under
the kingdom Protista has solved many
problems, particularly related to the position
of organisms like Euglena.
Elevation of the group fungi to the status of a
kingdom is justifiable since fungi totally differ
from other primitive eukaryotes like algae
The five-kingdom classification has certain
The kingdoms Monera and Protista include
diverse, heterogeneous forms of life. In both
the kingdoms there are photosynthetic
(autotrophic) as well as non-photosynthetic
Both the kingdoms include organisms which have cells
with cell wall as well as without cell wall.
Viruses have not been given proper place in this system of
Due to the absence of a cellular organization viruses
cannot be placed with either prokaryotes or eukaryotes.
They are considered as intermediate between living and
non-living systems. Viruses are active and show
reproduction only inside the host cell. In the free state
they are totally inactive. They may even be purified and
crystallized like chemical substances. Viruses have a
genetic material represented by either DNA or
RNA, surrounded by a protein sheath. Viruses reproduce
by using the metabolic machinery and raw materials of the
The five kingdoms currently accepted by
most (but not all) scientists are the Monera
Kingdom, the Protist Kingdom, the Fungi
Kingdom, the Plant Kingdom, and the Animal
The Five Kingdoms – Monera
The Monera Kingdom consists of unicellular
lifeforms. Unicellular means that they only
have one cell. Moneran cells are far simpler
and more basic than the cells of other
Monera are classified into two phyla, or
groups, autotrophs and heterotrophs.
Autotrophs are able to create their own
food, similar to plants. Heterotrophs cannot
create their own food, and so must rely on
autotrophs as their food source.
Bacteria are commonly placed in the Monera
Kingdom. Monera are considered by many
scientists to be the oldest lifeforms on
Earth, and the ancestors of all the other types
of life that have since evolved.
The Protista Kingdom consists of unicellular
lifeforms (lifeforms with only one cell) who
have a nucleus. The primary difference
between protists and monera is that
protists are more complex, having a
The Fungi Kingdom is made up of a variety
of different fungi. For many years, it was
believed that fungi were plants. Today we
know that fungi are different from plants in
some very important ways.
unlike plants, fungi cannot make their own
The Plantae Kingdom is made up of all the
plants that you see each day. Most plants
are multi-cellular, meaning that they consist
of many cells. Different types of plants
include trees, grass, flowers, and some
types of algae.
Plants use the light from the Sun to produce
their own food.
Like many other lifeforms, animals are
multi-cellular. These cells come
together, forming tissues, organs and organ
systems, that help sustain the life of the
animal. From elephants to snails, animals
come in many shapes and sizes, and can be
found all over the world.
Animals cannot make their own food. They
must rely on other living things, such as
plants, fungi, and other animals to sustain them.