Shastri ji for neet
1. The Living World
— Characteristics of Living Beings
— Taxonomy
— Systematics
— Biodiversity
— Taxonomical Aids
Biodiversity
It is the degree of variability among living organisms. It includes all
the varieties of plants and animals. It encompasses all the ecological
complexes (in which the diversity occurs), ecosystem, community
diversity, species diversity and genetic diversity. It comprises all the
millions of species and the genetic differences between them.
Systematics
It is the study of the biodiversity. It attempts to classify the diversity of
organisms on the basis of following four fields viz, identification,
classification, nomenclature.
1. Identification
It aims to identify the correct name and position of an organism in the
already established classification system. It is done with the help of
keys. Key is a list of alternate characters found in organisms. An
organism can be identified easily by selecting and eliminating the
characters present in the key.
2. Classification
It involves the scientific grouping of identified organisms into
convenient categories or taxa based on some easily observable
and fundamental characters. The various categories which show
hierarchical arrangement in decreasing order are
Kingdom → Phylum → Class → Order → Family → Genus → Species
3. Nomenclature
After classification, organisms are subjected to a format of two-word
naming system called binomial nomenclature. It consists of two
components, i.e., generic name and specific epithet. For example, in
Mangifera indica, ‘Mangifera’ is the generic name and ‘indica’ is the
specific name of mango. This system was proposed by C Linnaeus
(a Swedish Botanist) in (1753) in his book Species Plantarum.
Polynomial system of nomenclature is a type of naming system
containing more than two words. Trinomial system is a component of
polynomial system and contains three words. Third word represents
the sub-species and first two-words remain the same as in binomial
system.
Systematics
It is the study of the biodiversity. It attempts to classify the diversity of
organisms on the basis of following four fields viz, identification,
classification, nomenclature.
1. Identification
It aims to identify the correct name and position of an organism in the
already established classification system. It is done with the help of
keys. Key is a list of alternate characters found in organisms. An
organism can be identified easily by selecting and eliminating the
characters present in the key.
2. Classification
It involves the scientific grouping of identified organisms into
convenient categories or taxa based on some easily observable
and fundamental characters. The various categories which show
hierarchical arrangement in decreasing order are
Kingdom → Phylum → Class → Order → Family → Genus → Species
3. Nomenclature
After classification, organisms are subjected to a format of two-word
naming system called binomial nomenclature. It consists of two
components, i.e., generic name and specific epithet. For example, in
Mangifera indica, ‘Mangifera’ is the generic name and ‘indica’ is the
specific name of mango. This system was proposed by C Linnaeus
(a Swedish Botanist) in (1753) in his book Species Plantarum.
Polynomial system of nomenclature is a type of naming system
containing more than two words. Trinomial system is a component of
polynomial system and contains three words. Third word represents
the sub-species and first two-words remain the same as in binomial
system.
Codes of Biological Nomenclature
There are five codes of nomenclature which help to avoid errors,
duplication and ambiguity in scientific names.
There are five codes of nomenclature which help to avoid errors,
duplication and ambiguity in scientific names.
These codes are as follows
ICBN International Code of Botanical Nomenclature
ICZN International Code of Zoological Nomenclature
ICVN International Code of Viral Nomenclature
ICNB International Code for Nomenclature of Bacteria
ICNCP International Code for Nomenclature for Cultivated Plants
