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Introduction
Every organism whether plant or animal is unique in itself. There is a wide diversity in the flora (plants) and fauna (animals) in the world. The diversity we see today is the result of 3.5 billion years of organic evolution.
Importance of Classification
By making a comparative study and assorting the similarities and differences amongst the various varieties of species, organisms can be classified into groups or sets.
Nomenclature
Carl Linnaeus, father of modern botany, was a Swedish naturalist who laid the foundation of modern classification and nomenclature in 1758.
Classification of Plants and Animals
cellulose cell wall surrounds the cell membrane. Keep growing through out their life and are localised in the apical meristem.
Plant Kingdom
The plant body is not differentiated into stem, root and leaves but is in the form of an undivided thallus.
Animal Kingdom
The Animal Kingdom is divided in several phyla mainly on the basis of the cell organisation, symmetry, presence or absence of notochord and body cavity. Animals are arranged progressively from simple single-celled protozoans to highly complex mammals.
Phylum Protozoa (Primitive Animals)
Locomotion with the help of finger-like projections called pseudopodia, cilia or flagella.
Phylum Porifera (Sponges)
The simplest multicellular animals. The cells are loosely held together and do not form tissues. Ostia (pores) are present all over the body, with a single large opening on top called osculum.
Phylum Coelenterata (Cridaria)
The outer layer has tentacles armed with stinging cells cnidoblasts which can release venom into the victim. The inner layer encloses a body cavity called gastro vascular cavity.
Phylum Platyhelminthes (Flatworms)
Body in dorsoventrally flat and leaf like or ribbon-like with bilateral symmetry. The body cavity has only one opening which serves as both the mouth and the anus.
Phylum Aschelminthes (Round or Thread Worm)
Triploblastic body showing bilateral symmetry. Alimentary canal begins with the mouth and ends with the anus.
Phylum Annelida (Segmented Worms)
Body is covered by a non-chintinous cuticle which may have chitinous setae, or parapodia. Reproduction is generally sexual, but some may reproduce asexually by rejuvination i.e, by regrowing broken segments.
Phylum Arthropoda (Animals with Jointed Legs)
This is the largest phylum with almost 80% of the animals kingdom in this phyla. Body is bilaterally symmetrical and segmented. It is divided into head, thorax and abdomen.
Phylum Mollusca
Aquatic in habitat but some land forms are also seen. Body is soft and divided into three regions (head, dorsal visceral mass and ventral foot).
Phylum Echinodermata
Body is radially symmetrical, star shaped, spherical or elongate, Exoskeleton is spiny. Head is absent and five radially arranged arms present.
Phylum Hemichordata
Have characteristics of both invertebrate and chordate. Body is divided into proboscis, cottar and trunk.
Phylum Chordata
A rod like structure called notochord lying above the digestive tract. A tubular nerve cord lying above the notochord.
