Robert Whittaker (1959).

The criteria for classification of plant kingdom into divisions depend upon:
(a) differentiation of plant body components,
(b) presence of transport (conduction) tissues,
(c) ability to produce seeds, and
(d) enclosure of seeds in fruits.
On these basis animals cannot be classified because animals do not exhibit these characteristics. Animals on the other hand are classified on the basis of presence or absence of coeloem, symmetry, features of embryonic development and organisation of cells to form tissues and organ, etc.

Major divisions in kingdom plantae are-
(i) Thallophyta
(ii) Bryophyta
(iii) Pteridophyta
(iv) Gymnosperms
(v) Angiosperms.
Basis for classification plantae division:
1. Whether the plant body has well differentiated, distinct components.
2. Whether the plant body has special tissues for the transport of water and other substances within it.
3. Whether the plants bear the seeds or not.
4. Whether the seeds are enclosed within fruits or not.

The basis for grouping organisms into five kingdoms are:
(i) Whether the organisms are made of prokaryotic or eukaryotic cells.
(ii) Whether the organism is unicellular i.e., a cell living singly or organised into multicellular and thus complex organisms.
(iii) Whether the cells have a cell wall or not.
(iv) Whether they prepare their own food or get their food from outside.

In spite of certain external differences, plants and animals show a number of very obvious similarities which are as follows:
(i) Plants and animals are made up of microscopic units-the cell.
(ii) Both contain living substance protoplasm.
(iii) Certain life processes i.e., respiration, digestion, reproduction, assimilation etc. take place in both the groups in identical manner.
 (iv) Both show response to external stimuli.
(v) They both show growth.
(vi) Both reproduce and pass on their hereditary characters to the offspring by the same mechanism.

The practice of naming is one of the greatest inventions of man. Millions of animals and plants are named differently in different languages in different parts of the world. It means the names used for one organism differs from place to place. For example, Argemone a common weed has as many as ten to twele Hindi names alone. Some call it 'Firangi Dhatura', Sial Kanta', 'Pila Dhatura', 'Bharband', 'Kandhari', 'Satya nasi buti', 'Katela', 'Jahriber', 'Ugar Kanta' etc. Same thing is applicable to animals and other plants. Sometimes the common names are misleading. Same name may be used for different organisms in different parts.
To avoid this confusion Linnaeus gave a system in which an organism is given a name with two components-the first part is the generic name and the second part is the specific name. Thus the scientific name of common cat is Felis domestica, and that of tiger is Felis tigris. This system of giving a name with two components to an organism is called 'Binomial system of nomenclature'. The scientific names thus given to the organism are recognized all over the world. Hence, confusion is avoided on this aspect.

(a) Definition of classification. Arranging the things on the basis of similarities and differences in various groups is known as classification.
Significance of classification:
(i) Classification helps us in exploring the diversity of life forms.
(ii) Classification of organism indicates the interrelationship amongst different groups of organisms. Thus classification of life forms is related to their evolution.
(b) Plant                    Plant Division
(i)  Spirogyra             Thallophyta
(ii)  Fern                    Pteridophyta
(iii) Funaria                Bryophyta
(iv) Pinus                   Gymnosperm
(v) Apple tree             Angiosperm
(vi) Mustard plant       Angiosperm

Plants and Animals differ as given in the table below:

(a) Amphibia.  They are cold blooded animals that have three chambered heart e.g., Frog.
Aves. They are birds. All birds are warm blooded animals and have a four chambered heart.
(b) (i) Sea horse - Class Pisces
(ii) King cobra - Class Reptilia

Difference between bilateral and radial symmetry. An animal is said to bilateral symmetry, if it has two equal but opposite right and left halves when it is cut lengthwise in the middle vertical plane. For example, frog.
An animal is said to have radial symmetry, if it is symmetrical with respect to any plane passing through its longitudinal axis. Any plane passing longitudinally through any diameter divides the body into equal halves. For example, Hydra shows a radial symmetry.

Main Features of Vertebrata/chordates.
(i) Vertebrates have bilaterally symmetrical body.
(ii) They have true vertebral column and internal skeleton.
(iii) They have dorsal nerve cord.
(iv) They are Triploblastic.
(v) They are coelomate.
(vi) Respiration is mainly through lungs in land vertebrates and by gills in aquatic.

Diploblastic: The animals whose body is developed from two layers of gastrula-ectoderm and endoderm are called diploblastic. For example, coelenterates (Hydra).
Triploblastic: The animals whose body develops from three layers-ectoderm, mesoderm and endoderm of gastrula are called triploblastic e.g., tapeworm.