The Living World
Living organisms
The living creatures of all kinds are known as living organisms.
For example, all plants, animals, and microorganisms are living organisms.
Characteristics of Living Organisms
Living organisms are made up of cells The organisms made up of a single cell are called
unicellular and those made up of many cells are called multicellular.
All living organisms require food The organisms that can synthesize their own food are
called autotrophs such as green plants. The organisms that cannot make their own food but
depend upon either plants or other animals are called heterotrophs.
All living organisms show growth.
All living organisms respire The process of taking in oxygen and giving off carbon dioxide
is called external respiration. On the other hand, when oxygen is used by cells to release
energy, the process is called internal respiration.
All living things respond to stimuli.
All living things excrete The process of elimination of waste material from the body is
called excretion.
All living things reproduce The process by which living organisms produce more of their
kind is called reproduction.
Differences between Living things and Non Living things.
Living things
They are made up of cells
They show movement, but the energy for
movement comes from within the
organism.
Non Living things
They are not made up of cells
They show movement by taking external
force or energy.
They need food
They do not need food
Growth is irreversible
Growth is reversible
Respiration occurs for oxidizing food to
release energy
Reproduction occurs in living things
Differences between Plants and Animals
They do not need respiration.
Non living things do not reproduce
Plants
They can make their own food by the
process of photosynthesis. They are
known as autotrophs.
Animals
They cannot make their own food. They
are heterotrophs.
They show movement but cannot
show locomotion i.e. they cannot
They show movement as well as
change their position from one place locomotion.
to another.
They show response to stimuli but
lack sense organs.
They grow throughout their life.
They also show response to stimuli
and have well-developed sense
organs.
They stop growing once they reach
their adult form.
Nomenclature
The process to standardise the naming of a living organism is known as
nomenclature.
The process of assigning a pre-existing taxon name to an individual organism is
identification.
The system of providing a name with two components Generic name and specific
epithet is known as Binomial nomenclature.
Binomial nomenclature was given by Carolus Linnaeus.
The biological names are generally in Latin and written in italics underlined when
written by hand. Example: The biological name of mango is Mangifera indica.
The first word in a biological name (e.g. Mangifera) represents generic name, which
always starts with capital letter while the second component (e.g. indica) represents
the specific epithet that starts with a small letter.
IUBN International Code for Botanical Nomenclature and IUZN International Code of
Zoological Nomenclature are responsible for approving a scientific name and ensuring that
this name has not been given to any other plant or animal.
Taxonomical Aids
Taxonomy is the branch of biology that deals with identification, naming, and
classification of organisms.
Taxonomical aids are the procedures and techniques used to store and preserve
information as well as specimens of various plants and animals.
These help in identification, naming, and classification of the organisms.
Herbarium
It is the storehouse of collected plant specimens.
Collected plant specimens are dried, pressed, and preserved on sheets and then
arranged systematically according to the universally accepted system of classification.
Herbarium sheet contains label regarding date, place of the collection, scientific name,
family, collectors name, etc. of the specimen.
Botanical gardens
It has the collection of living plant species that are grown for identification and
reference.
Each plant contains labels indicating their scientific name and family.
Some famous botanical gardens are Indian Botanical Garden, Calcutta (largest in
India), Royal Botanical Garden, Kew (largest in world till date), and National Botanical
Research Institute.
Museum
It is the repository that has a collection of various plant and animal specimens that are
preserved for study and reference.
The organisms are preserved either in preservative solution or in the form of dry
specimens.
It often has a collection of skeletons of animals also.
Zoological parks
Wild animals are kept in protected environments.
Provides opportunity for studying the behaviour and food habits of the animals
Key
Keys are used for identification of plants and animals based on similarities and
dissimilarities.
Manuals, monographs, and catalogues are other means of recording descriptions.
Manuals help in the identification of names of various species of organisms in a given
area.
Monograph is a detailed and well-documented work on any particular taxon.
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