• BIOLOGY: - The word biology was taken from
Greek. Bio means life, logy means study of.
Therefore biology means study of life.
The branch of science, which deals with
the study of structure, function, habitat and
economic importance of organism is called
• Aristotle was considered as father of biology.
• Life: - The living activity shown by an organism
from birth to death is called life.
• Characteristics of living organism: • Growth: The living things exhibit internal growth
or intersusception growth.
• Reproduction: During the life span all living
organism reproduce themselves. Some organisms
reproduce asexually & some sexually.
• Metabolism: The living organism have
metabolism. The total sum of chemical reaction
occurs in side the organism is called metabolism.
• It is classified into 2 types.
• Anabolism: - It is the
chemical reactions in
which large molecules
are builds from
• These are
• EX: photosynthesis
• Catabolism: - It is the chemical reactions in
which break down of large molecules in to
• These are distructive reactions
• EX: Cellular respiration, in which glucose is
broken down in to CO2 & H2O.
• cellular organization: All living organism have
cellular organization. The cell forms the structural
and functional unit of life.
• The organisms having only one cell are called
unicellular organisms. EX: amoeba, paramecium,
• The organisms having millions of cells showing
organ and organ systems are called multicellular
organism. EX: All plants and animals.
• Size: The livings organism have definite farm and
• Consciousness: All living organisms show response
• They have interim relation with surrounding
• Biodiversity : Term used to refer to the number
of varieties of plant and animals in region on
• Need for classification : living organisms are
classified into categories because that could be
named, remembered, studied and understood.
• Nomenclature: Binomial nomenclature was
first introduced by Carolus Linnaeus. He
published the book ‘Systema Naturae’.
• The scientific naming of an organism using
two words is called Binomial nomenclature.
• Each scientific name has two components Generic name + Species name.
• Rules for Nomenclature :
1. Latinised names are used.
2. First word is genus, second word is species
3. Printed in italics; if handwritten then
4. First word starts with capital letter while
species name written in small letter.
Ex: Mangifera indica.( mango)
• ICBN : International Code of Botanical Nomenclature
(for giving scientific name to plants.)
• ICZN : International Code of Zoological Nomenclature
(for giving scientific name to animals.)
• Taxonomy : Study of principles and procedures of
• Systematics : It deals with classification of organisms
based on their diversities and relationships among
them. Term was proposed by Carlous
• Taxonomic Hierarchy : It is the arrangement of various
taxa of classification
• Species → Genus → Family → Order → Class → Phylum
(for animals) Division (for plants) →Kingdom
• SPECIES: Group of individuals having fundamental
similarities in characteristics and successful
reproduction takes place among themselves form
E.g:Panthera tigris,Panthera leo
• Solanum tuberosum, Solanum nigrum.
• GENUS :
• It consists of a group of related species.
Genera are aggregates of closely related
• E.g:Panthera leo ,P pardus (leopard) ,P tigris
• It has a group of related genera.
• E.g:family Solanaceae includes genera
solanum(tomato,potato) , petunia & datura.
• Family Felidae includes genera panthera
(lion, tiger ,leopard) &Felis(cat)
• It is the group of families which include a few
• E.g:order polynomial includes family solanaceae &
• E.g: carnivora includes family felidae &
• CLASS :
• It includes all related orders having few similar
• E.g: class mammalia includes order Primata
(monkey, gorilla,gibbon) &carnivora.
• E.g:class Dicotyledonae includes order
• PHYLUM or DIVISION:
• It includes related classes having few similar
• E.g:phylum Chordata includes classes fish
,amphibia, reptilia, aves &mammalia.
• Division angiospermae includes class
dicotyledonae & monocotyledonae.
• TAXONOMICAL AIDS:
• Taxonomic studies of various species of plants,
animals and other organisms require correct
classification and identification.
• Identification of organisms requires laboratory
and field studies.
• The other taxonomical aids are,
• Botanical Garden
• Zoological Park
• Herbarium is a store house of collected plant
specimens that are dried, pressed and preserved
• Museums have collections of preserved plant and
• Zoological Parks are the places where wild
animals are kept in protected under human care.
• Key is another taxonomical aid used for
identification of plants and animals based on the
similarities and dissimilarities.