2. DEFINITION
CLASSIFICATION
A system of arrangement of
organisms into different groups on the
basis of their similarities, differences
and relationship.
3. Classification is also known as
TAXONOMY.
It is the branch of science which
deals with and is defined as
Identification, nomenclature and
classification of organisms with certain
principles.
4. NEED / IMPORTANCE OF
CLASSIFICATION
1. It makes the study of wide variety of organism easy.
2. The study of organisms is made easy as learning about an
organism belonging to a specific ‘GROUP’ is easy.
3. It also helps to understand the interrelationship among different
organisms.
4. Many other biological sciences depend on the correct knowledge
of characteristics of organisms which classification provide. Eg in
ecology, forestry, biogeography , applied biology.
5. Hierarchy of Classification
Groups
As classification deals with grouping the organisms
,which are called TAXA {Taxon} , each taxa is given a name
and they are arranged in a specific pattern in the flowchart of
order/sequence.
The organisms that closely resemble are placed in a
taxon and further the taxa related are put together in a
larger taxon. There are 7 such taxa.
6. CLASSIFICATION OF LIVING ORGANISMS
KINGDOM [largest]
PHYLLUM/DIVISION
CLASS
ORDER
FAMILY
GENUS
SPECIES [smallest]
7. Aristotle gave the first but crude classification.
Carolus Linnaeus in the 18th century gave the first
basis of modern classification. He divided organisms
into 2 kingdoms : PLANTAE [ Plant Kingdom] and
ANIMALIA [ animal kingdom] because he could see
only these .
Ernst Haeckel , a german zoologist , further added
one more kingdom PROTISTA which included all
unicellular organisms.
8. Robert Whittaker , as more developments in biological
sciences happened, found that there were significant
differences among organisms of the protista and hence he
defined two more kingdoms MONERA , FUNGI.
Thus the 5 kingdom classification by R.H.
Whittaker came into existence, which is still
the basis of modern classification.
9. Whittaker based his classification on 4 factors
namely :
1. Cellular structure- whether the organism is Prokaryotic or
Eukaryotic.
2. Cellular organization- whether the organism is Unicellular or
Multicellular. In multicellular organisms what is the level of
organization.
3. Mode of source of nutrition- whether the organism is
Autotrophic or Heterotrophic.
4. Phylogenetic relationships- phylogeny means evolutionary
history of a species.
11. Evolution and Classification
Darwin's theory of evolution states that all present – day
organisms have originated from the same source and during the
course of time have evolved into complex organisms by bringing
about variations within it’s body to adapt to the changing
environment.
This can be easily seen and studied in the classification because it
is an arrangement where phylogeny is considered as one of the
main criteria.
12. Classification and Nomenclature
Nomenclature means to name an organism.
Naming an organism is essential to identify it as well as distinguish it from the
others.
In biology all organisms are given specific scientific names. This is done to
avoid any confusion when an interaction is held among people of different
vernacular regions.
Binomial Nomenclature : It was proposed by Carolus Linnaeus, according to
this a scientific name consists of 2 components, first the generic name and
second is the specific name.
15. The Monera (Bacteria) Kingdom
Simplest form of life- Unicellular,
microscopic
Do not have a nucleus-prokaryotic
no chlorophyll - saprophytic or
parasitic.Absorb food
These are bacteria and cyanobacteria
which is also referred to as blue green
algae
Bacteria can be found anywhere, it can
grow in hot or cold places
Bacteria can feed on many different
things
16. The Protista Kingdom
Single Celled
All have a nucleus -
Eukaryotic
Absorb, ingest, and/or
photosynthesize food -
Autotrophic and
heterotrophic
Examples are:
paramecium, amoeba
Amoeba
Paramecium
17. Eukaryotic
Made up of hyphae
No root, stem and leaf but
fixed to the substrate
No chlorophyll
– Saprophytic or parasitic
Reproduce by forming
spores
Mushrooms, yeasts,
moulds are all forms of
fungi
The Fungi Kingdom
18. The Plantae Kingdom
Second largest group of
living things on earth
Eukaryotic , Multicellular
Have cell wall
Lack mobility
Most plants contains
photosynthetic pigments
(e.g. chlorophyll) for
photosynthesis
– Autotrophic
Can be divided into two
groups:
– Non-flowering plants
– Flowering plants
21. Classification of Plants
Plants are divided into the four main
groups based on two major characteristics:
presence or absence of vascular tissue
and seeds.
Vascular tissue transport substances such
as water, minerals and sugars throughout
the plant.
Seeds are structures that contain an
embryo, stored food and an outer coat.
22. Thallophyta
• Plants that do not have
tubes to carry water up
the plant or tubes to
carry food made in the
leaves down the plant
Aquatic
May be unicellular or
multicellular
No root, stem or leaf
Contain photosynthetic
pigments (e.g.
chlorophyll) for
photosynthesis
example - Sea weed,
diatoms, spirogyra
23. Bryophyta (Mosses)
With simple leaves and
stems
No root; with rhizoids for
anchorage and absorption of
water
Reproduce by spores
No vascular tissues
Found in damp area
Non-vascular land plants do
not contain any conducting
tissues and are often
referred to as bryophytes.
These plants are small,
grow close to the ground
and include mosses and
liverworts.
25. Pteridophyta (Ferns)
With true roots, stems,
leaves and vascular tissues
Seedless vascular plants
contain vascular tissues
but do not produce seeds.
Reproduce by spores.
Live in damp places.
This group includes
horsetails, ferns and club
mosses.
26. Seed Producing Vascular Plants
Spermatophytes
Seeded vascular plants also contain
extensive vascular tissue and the majority
of species in the plant kingdom are in this
group. They have a seeds that contain an
embryo, a nutrient supply and a protective
outer coat.
Seeded vascular plants are divided into
angiosperms and gymnosperms.
27. Gymnosperms
Reproduction by producing seeds that do
not develop within an enclosed structure
– Seeds develop in cones, not enclosed by fruits
⇒ naked seeds
Needle-shaped leaves to reduce water loss
28. Angiosperms
Angiosperms are flowering plants
with seeds that develop inside a
protective structure.
flowers for reproduction.
Seeds are produced inside the
fruit (matured ovary)
29. Two groups of flowering plants
MonocotyledonsDicotyledons
Cotyledons Two One
Leaf venation Netted (Reticulate) Parallel
Root system Tap root system Fibrous root
system
