Table of Contents
Introduction:
The five kingdom classification that we are studying now is not the initial one. Linnaeus first came up with two kingdom classifications: Plantae and Animalia. He classifies based on movement and growth limit. In Plantae, he placed living organisms that are not able to move and have unlimited growth and in Animale, the living organisms are able to move but growth is limited. But due to this classification so many doubts arose regarding the placing of certain species. The two-kingdom classification lasts for longer but not forever. It fails to differentiate eukaryotes, prokaryotes, photosynthetic, non-photosynthetic, unicellular, and multicellular. There are some living organisms that we can not keep under Plantae or Animalia. At that time there was so much confusion even some scientists had discovered three kingdoms, four kingdoms, etc., but in all those five kingdoms classification is adopted by many people and even now we only study about that widely. Five kingdom classification divides living organisms based on their mode of nutrition, cell structure, thallus organization, and reproduction which was done by Whittaker.
Overview:
The five kingdom classification system was proposed by R.H. Whittaker in 1969. The system of arranging living organisms in groups or sets depending upon their likeness and variance is known as classification. By doing this we are able to study a wide variety of living organisms in an easy way. Whittaker classified living organisms in these five kingdoms based on the structure of cell, mode of nutrition, source of nutrition, body organization, reproduction, and interrelations.
Ernst Haeckel, Whittaker, Carl these biologists attempted for border classification but in these all we widely used and accepted the five kingdom classification.
Robert H Whittaker classified living organisms broadly into five kingdoms in 1969.
They are as follows:
- Kingdom Animalia
- Plantae
- Fungi
- Protista
- Monera
Kingdoms are divided into subgroups at various levels for making our study and observation easy. This is the flowchart showing the hierarchy of classification.
Kingdom—> Phylum—>Class—> Order—> Family—> Genus—-> Species
Kingdom Monera:
Monerans have bacteria. Bacteria occur everywhere in nature, some are harmful and some are useful. Under the monera kingdom, prokaryotes are there which possess a cell wall. The cell wall is made up of polysaccharides. The mode of nutrition of monera can be autotrophic or heterotrophic. Some are photosynthetic and some or not. Monerans are unicellular which don’t have a well-defined nucleus and also lack organelles. Monera is further classified into archaebacteria and eubacteria.
Archaebacteria – are primitive and simple forms of bacteria that can survive in extreme conditions.
Eubacteria – these living organisms lack membrane-bound nuclei.
Types of monerans/ bacteria:
Bacteria are classified into four types based on their shape and they are:
- Coccus- bacteria under this are spherical or oval-shaped.
- Bacillus:- rod-shaped bacteria are present under this section.
- Vibrium:- these bacteria are comma-shaped bacteria
- Spirillum:- bacteria present in this group are spiral or coiled shaped.
Examples of monerans are bacteria, cyanobacteria, and mycoplasma.
Kingdom Protista:
Protists are eukaryotic living organisms. They have cilia and flagella for mobility on their surface.
Reproduction takes place in the form of cell fusion and zygote formation. Protists are heterotrophic and also autotrophic. Protists are further divided into
Chrysophytes:
the desmids which are known as golden algae and diatoms fall under this group. Chrysophytes are mainly found in marine and freshwater habitats.
Dinoflagellates:
They are usually photosynthetic. They are in red, blue, brown, green, or yellow depending upon key pigments in their cells.
Euglenoids:
Most of them live in freshwater and motionless water. Instead of the cell walls, they contain a protein-rich layer called a pellicle.
Slime moulds:
They are saprophytic in nature and they form accumulation which is called slime moulds.
Protozoans:
protozoans are heterotrophs that survive either as parasites or predators.
Examples of Protista are algae-spirogyra, euglena. Amoeba, paramecium etc.
Kingdom fungi:
Fungi are filamentous except yeast which is single-celled. Fungi consists of long thread-like constructions called hyphae. The web of hyphae is known as mycelium. Coenocytic hyphae are unbroken tubes that are jam-packed with multinucleated cytoplasm. The Fungi cell wall consists of polysaccharides and chitin. These are saprophytes or heterotrophic. Several fungi also survive as symbionts and some are parasites. Some of the symbiont fungi are in association with algae. Some symbiont fungi live in association with roots of higher plants such as mycorrhiza. They are multicellular too. Fungi reproduce sexually or asexually by spore formation.
Examples of fungi are yeast, mushroom, aspergillus, etc.
Kingdom Animalia:
All living organisms having multicellular, which are heterotrophs and lack cell walls are present in this group. Animals are directly or indirectly dependent on plants for food. The mode of nutrition is holozoic which is taking food by mouth and using an internal cavity for digestion. Animals adapt for locomotion. A sexual mode of reproduction takes place. The most distinguishing feature is that of the presence of sensory organs and the nervous system. The animal kingdom has been divided into many phyla and classes. Some of the phyla are Porifera, Coelenterata, Arthropoda, etc. They have been divided into sub-classification vertebrates- these organisms have a backbone and those who don’t have a backbone are known as invertebrates.
Examples of Animalia are monkeys, birds, hydra, and, jellyfish, etc.
Kingdom Plantae:
Plantae has eukaryotes with chloroplast. Most of them are autotrophic in nature but some are heterotrophic too. The cell wall mainly contains cellulose. Based on the vascular tissue, kingdom Plantae is divided into further divisions namely Thallophyta, Bryophyta, Pteridophyta, gymnosperms, and angiosperms. Reproduction is done either sexual or asexual. Plants are divided into many categories based on their genome type, flowering, etc.
Examples of Plantae are mango, ferns, pines, etc.
Also read: Five Kingdom Features
Frequently Asked Questions (FAQs):
Question 1: What is kingdom classification?
Answer: The system of arranging living organisms in groups or sets depending upon their likeness and variance is known as classification. Kingdom classification is the highest classification into which organisms are grouped in taxonomy
Question 2: What basis are the living organisms in the five kingdoms classified?
Answer: Whittaker classified living organisms in these five kingdoms based on the structure of the cell, mode of nutrition, source of nutrition, body organization, reproduction, and interrelations.
Question 3: What are different levels of classification?
Answer: Kingdoms are divided into subgroups at various levels for making our study and observation easy. This is the flowchart showing the hierarchy of classification.
Kingdom—> Phylum—>Class—> Order—> Family—> Genus—-> Species
Question 4: Who proposed the five kingdom classifications?
Answer: The five kingdom classification system was proposed by R.H. Whittaker in 1969. The system of arranging living organisms in groups or sets depending upon their likeness and variance is known as classification. By doing this we are able to study a wide variety of living organisms in an easy way. Whittaker classified living organisms in these five kingdoms based on the structure of the cell, mode of nutrition, source of nutrition, body organization, reproduction, and interrelations. Ernst Haeckel, Whittaker, Carl these biologists attempted for border classification but in these all we widely used and accepted the five kingdom classification.
