Biological Classification; structure of a cell

2. Definite size and shape
Organisation
Life Span
Reproduction
Response to stimuli
Respiration
Cellular nature
Growth
Movement
Nutrition

3.  The method of identifying distinct features
among different organisms and placing them
into groups that exhibit their most significant
features and relationship.
 The main purpose is to organise the huge
number of plants, animals and
microorganisms into categories that could be
named, remembered and studied.

4. Systematics
discipline that deals with the kinds and diversity of all
organisms and the existing relationships amongst
themselves.
Taxonomy
the functional science that deals with identification,
nomenclature and classification of different organisms in
the world.
derived from Greek words taxis (arrangement) and nomos
(law)

5.  Earliest clue -Vedas and Upanishads (1500 BC to 600
BC)
 Post Vedic literature – Susruta Samhita (600 BC)
 Vrukshayurveda - Parashara
 Charaka Samhita – medicinal plants
 Aristotle (384 -322 BC)
 Theophrastus (370 -285 BC)
 John Ray (1627 - 1705) introduced the term ‘species’.

6.  Carolus (Carl) Linnaeus
– ‘Systema Naturae’ (1753)
- Two kingdom classification
- ‘the Binomial System of Nomenclature”
 Theory of Evolution- Darwin,Lamarck
 Ernst Haeckal – Phylogenetic tree

7.  Sir Julian Huxley
– introduced “New Systematics” (1940)
- Replaced morphological species definition by a
biological one.
 R.H. Whittaker
- Five kingdom Classification (1758)

8.  Artificial system of nomenclature
 Each plant/ animal is given a biological or
scientific name
 Name -in Latin/ Latinised
 Italicised or underlined
 Two parts: Genus- capitalised; Species –
lowercase
 Species name has to be different within same
species

9.  Introduced by Carl Linneaeus
 Broadly classified into plant and animal
kingdoms
 Taxonomic Hierarchy - the frame work by
which the taxonomic groups are arranged in
a definite order, from higher to lower
categories.

12. Basic Criteia for Classification:
a) Complexity of cell structure: prokaryotic and
Eukaryotic
b) Complexity of organisms: Unicellular or
multicellular
c) Mode of nutrition: Plantae (autotrophs), Fungi
(heterotrophs and saprobic absorption),
Animalia (heterotrophs and ingestion)

13. Basic Criteia:
d) Life style: Producers (Plantae), Consumers
(Animalia), Decomposers (Fungi)
e) Phylogentic relationships: prokaryotes to
eukaryotes, unicellular to multicellular
organisms