Two-kingdom classification, Biology

Two-Kingdom Classification

The history of taxonomy is as old as man himself. It may be traced back to prehistoric times because man had learnt to designate living organisms by specific names very early in his evolutionary history. Much before the advent of civilisation living things had been categorised into animals and plants. Hippocrates (460-370 BC), Aristotle (384-322 BC) and many others had tried to put some order into the chaos of the bewilderingly large number of different life forms. Aristotle appears to have been the first to attempt a logical system of classification. He classified animals on the basis of presence or absence of blood as Sanguineous (with blood) and Non-sanguineous (without blood). He believed that in evolution, life had been directed towards a perfect animal form, having blood (Table 1.6). He incorporated this idea which is a hierarchical system of classification In his book entitled 'Scala Naturae'. He also recognised two kingdoms in the living world i.e., Plantae and Animalia. The former included mainly immobile forms, while the latter embraced mobile forms. We also know that one of the major differences between the two is that the members of Kingdom Plantae are autotrophic and obtain their food mostly by photosynthetic means and those of Kingdom Animalia are heterotrophic and obtain their food by ingestion.

Table: Aristotle's 'Scale of life' or Scala Naturae.

1839_Two-Kingdom Classification.png


Kingdom Plantae was later divided by biologists into two subkingdoms,

  1. Thallophyta containing the phylum Algae (with chlorophyll) and Phylum Fungi (without chlorophyll) and
  2. Embryophyta with phylum Bryophyta (liverworts and mosses) and Phylum Tracheophyta (vascular plants).

Kingdom Animalia, on the other hand, was divided into Subkingdoms Protozoa containing unicellular forms and Sub Kingdom Metazoa including sponges and other multicellular organisms. A third Sub Kingdom Parazoa was later created and the sponges were shifted to this Sub Kingdom due to their intermediate position. between uni and multicellular organisms.

Posted Date: 1/12/2013 4:18:43 AM | Location : United States







Related Discussions:- Two-kingdom classification, Assignment Help, Ask Question on Two-kingdom classification, Get Answer, Expert's Help, Two-kingdom classification Discussions

Write discussion on Two-kingdom classification
Your posts are moderated
Related Questions
Neuston - Aquatic Ecosystem These are unattached organisms which live at the air-water interface such as floating plants and several types of animals. Some spend most of their

What is the concept of Lophophore? A unique double ring of hollow ciliated tentacles that surround the oral opening in some animal phyla. There is some debate as to whether the

How different are the respiration in fishes and the respiration in adult amphibians? In fishes gas exchange is completed by direct contact of water with the branchiae (gills).

Q. Investigations of food borne diseases? Most important aspect of food borne disease would be to collect the right sample. Now, what procedure to follow while collecting th

Q. Carbohydrates requirement during myocardial infarction? The protein intake generally remains the same as per the RDI i.e. 1.0 gm protein per kg body weight per day. Adequate

Explain the Periodontal consideration Periodontal consideration would include: Hard Calculus Build up:   Any index assessing the amount of calculus build up can be used .

Neural Circuits The simple all are none activities of a single neuron can hardly provide the adaptability needed for the constant changes faced by the organism in its internal

summarise the comparative anatomy of the digestive system of the invertebrate and the vertebrate.

Define Free Solution or Moving Boundary Method? The first electrophoresis technique used in the study of protein was free solution or moving boundary method devised by Tselius

Define uses isolated soybean proteins? Partially hydrolysed soy proteins possess good foam stabilization properties and can be used as whipping agents in combination with egg a