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
List three types of evidence used by systematic taxonomists to construct phylogenetic diagrams. Types of evidence contain the morphology of fossil and living species, patterns

What would be the advantage of using a patient's own stem cells e.g. blood stem cells, to treat his or her illness? The benefit of using stem cells from the patient being trea

Nursing Care of Common Cold: Relieve Nasal Congestion Clean the nasal passage to remove secretions. In  infants nasal aspirator can be used while  the older children can

Q. Define Lipoprotein Metabolism? Lipoproteins serve to transport absorbed dietary fat and endogenously synthesized cholesterol and triglyceride. Nevertheless, it is possible t

Curdlan Curdlan, a glucan with (1→3) is produced by bacterium  Alkaliqenus faecalis  var. myogenes and some related bacteria. It is a tasteless, odorless white powder, which sw


Define Clinical Significance and Risk Factors for Drug-Nutrient interactions? We are already aware of the fact that poor nutritional status can impair drug metabolism and the d

Problem 1: "Structural Genomics aims at determination of the 3D structure of all proteins". Describe with techniques Show genomic techniques for determination of 3D struc

Explain about the Celiac Disease? Celiac disease (also called gluten enteropathy) is an intestinal disorder that results from an abnormal  immunological reaction to gluten. u p

Q. What is Catharanthus roseus pharmaceutical compounds? This species yielded the alkaloids vincristine and vinblastine. Traditionally used by various cultures for the treatmen