Class 11th ncert biodiversity class notes for neet preperation... Easy and short notes for fast revision

Biodiversity and Taxonomy
Biodiversity:
Life / Living forms / varieties. Biodiversity is the total number and varieties of living organisms
present on planet Earth.
 Earth: 1.7–1.8 million taxonomically known species.
 Among these:
o 1.2 million are animals (mostly insects).
o 0.5 million are plants (mostly angiosperms).

Need for Classification
1. Huge number of plant and animal species present on Earth.
2. Difficult to study all of them individually.
3. To make the study of every organism easy, they are classified into
convenient categories or groups.

Taxonomy
Derived from two words:
 Taxis: Arrangement
 Nomos: Rules / Law
Definition: A branch of science which deals with the classification of living organisms by
following rules/laws.
 Term "Taxonomy" given by: A.P. de Candolle
 Father of Taxonomy: Carolus Linnaeus

Taxonomy and Systematics Overview
Taxonomy involves the following steps:
1. Characterisation: Organism is described according to all
morphological, anatomical, physiological, and behavioural properties.
2. Identification: Process by which an organism is recognized from other
already known organisms and assigned to a particular taxonomic
group.
3. Classification: Process by which an organism is grouped into
convenient categories on the basis of easily observable characters.
4. Nomenclature: Naming of an organism according to established
rules.

Systematics
Derived from "systema" – Systematic arrangement of living organisms.
Deals with:
1. Diversity of living organisms.
2. Evolutionary relationships among organisms.