Classification Of Organisms

1. Diversity in living organisms

Jagriti 01 Jan 1970

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As we have studied about the classification of the organism and the hierarchical order which deals with taxonomy, binomial nomenclature, and the concerned detailing. Now we will move to the discoveries, the kingdom classification and its need in life.

Diversity:

Earth stands for life. A place or heaven where diverse life forms exist. There are about 20 lac organisms known on Earth with a variety of differences in terms of organization, external form, habitat, nutrition and so on.

Five kingdom classification was proposed by Robert Whittaker in 1959,which includes Monera, Protista, fungi, Plantae, and Animalia

• Classification gives us a data that is significant to search, provides a proper systematic manner of species along with the data of their evolution.
• Carolus Linnaeus is known as the father of the Modern Taxonomy. He proposed a two-kingdom classification in 1758.
• Aristotle gave the classification of animals on the basis of land, water, and air.
• Primitive organisms are those organisms that have ancient body design while advanced organisms are those kinds of organism who have recently acquired body changes.
• Five kingdom classification was proposed by Robert Whittaker in 1959.
Five kingdom classification includes Monera, Protista, fungi, Plantae, and Animalia
• Carl Woese further divided Monera into Archaebacteria and Eubacteria.

The organization inside the cell:

• Prokaryotic cells: cells with no definite nucleus.
• Eukaryotic cells: cells with a definite nucleus.
• The organization of cells in the body:
• Unicellular: singer celled organisms.
• Multicellular: multi-cell organisms.

The category to obtain food:

• Heterotrophs: depends on other organisms for their food.
• Autotrophs: produce their own food.
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2. Classification of organisms - taxonomy

Jagriti 01 Jan 1970

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Hierarchy of group or order to explain the Taxonomy (the study of the classification of the organisms) are:

Domain

      Kingdom

          Phylum or division

              Class

                   Order

                        Family

                          Genus

                               Species

1. The domain is the highest order and species is the lowest order category.
2. Biologists, such as Ernst Haeckel (1894), Robert Whittaker (1959) and Carl Woese (1977) has classified all living organisms into broad categories called kingdoms.
3. The five-kingdom classification was proposed by Whittaker which is Monera, Protista, Fungi, Plantae, Animalia.
4. The naming culture ( of the different organisms) practiced uniformly across the world is called binomial nomenclature.
5. Rules of nomenclature:
   1. It consists of two words, the first denotes the genus (of the organism ) always begins with a capital letter and the second denotes the species , with a lower case letter.
   2. It is also known as a scientific name and must be written in Italic.
   3. For example- Human is Homo sapiens, the Tiger is Panthera tigris, etc.
   4. It makes our work easy and convenient and provides data that can be used universally to find or look for any species whether plants or animals.
6. Cells are fundamentally categorized into Eukaryotes and Prokaryotes where Eukaryotes are complex in structure while prokaryotes are the smallest and simplest in structure.

  In details we will be discussing in the next part.

3. The five kingdom Classification, characteristic features and differences.

Jagriti 01 Jan 1970

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Robert Whittaker has invented five-kingdom classification i.e., Monera, Protista, Fungi, Plantae, and Animalia. These are some important characteristic features of each kingdom.

Kingdom Monera:

1. The organism belonging to this group are prokaryotic, microscopic and unicellular.

 2. They have a lack of cell organelles as well as they do not have a well-defined nucleus.

3. Some organisms can synthesis their own food (autotrophs) while some can’t synthesis their own food and are dependent on others for food known as (heterotrophs). · Cell wall is present in some of the organisms while absent in others.

4. Blue-green algae, bacteria and mycoplasma etc are found in this group of classification.

Kingdom Protista:

1. This group consists of many types of unicellular Eukaryotes.

2. They have both autotrophic as well as the heterotrophic mode of nutrition.

3. They have defined the nucleus as well as membrane-bound organelles.

4. The organism found in this group has appendages, like hair-like cilia or whip-like flagella for moving around and for locomotion.

5. Protozoan, diatoms and unicellular algae etc are found in this group of classification.

Kingdom Fungi:

1. They are Eukaryotic non-green, very simple organisms.

2. They also contain a cell wall that is made up of a tough complex sugar layer known as chitin.

3. They perform heterotrophic mode of nutrition.

 4. Most of them are saprophytes (organisms who are dependent on dead and decaying organic plant and matter for food) and some are parasitic too.

 5. Yeast, penicillium, and mucus etc are found in this kingdom.

Kingdom Plantae:

1. They are multicellular, eukaryotic organisms.

2. They have a cell wall made up of cellulose engrossed with other organelles.

3. Most of them have green pigment (chlorophyll), ultimately performs photosynthesis and thus known as autotrophs.

4. This kingdom is further classified as Thallophyta, Bryophyta, Pteridophyta, gymnosperms, and angiosperms.

Kingdom Animalia:

1. This kingdom posses multicellular eukaryotes without any cell wall, thus organelles are suspended in the given matrix inside the cell.

2. They are heterotrophic in nature.

3. They are further classified as Porifera, Coelenterata, Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Ununchordata and Vertebrata.

4. They almost include all the animals.