The basic two-kingdom classification system, which divides plants and animals into two groups, was ineffective for studying species that did not fit into either of the divisions. Some organisms bear no resemblance to plants or animals. As a result, to classify and study all creatures, a larger system was required to first classify and group them all.
Organisms are classified into five kingdoms based on:
Individual components required by an organism to carry out various life activities make up a cell structure.
- Body Organisation refers to how an organism’s body is organised on multiple levels. In humans, for example, cells combine to form tissues, tissues combine to make organs, and organs are organised into organ systems, and so on.
- The process through which an organism receives and consumes nutrients is referred to as the mode of nutrition. It can be either autotrophic or heterotrophic. They are then subdivided into different categories. To learn more about Mode of Nutrition, visit Vedantu’s website.
- How an organism reproduces is referred to as its mode of reproduction. It might be either sexual or asexual. Fragmentation, fission, budding regeneration, vegetative propagation, and other methods can be used. Vedantu can assist you in fully comprehending Modes of Reproduction.
- Phylogenetic Relationship (Evolutionary Development and Diversification) – Phylogenetic relationships, in simple terms, are the relationships that aid in determining how closely two organisms are linked by shared ancestry.
In 1969, Robert H Whittaker proposed the Five Kingdom Classification for studying organisms.
The System of the Five Kingdoms
According to this concept, there are five major groups:
- Animalia
- Plantae
- Fungi
- Protista
- Monera
Animalia
This category includes eukaryotic and multicellular creatures that lack a cell wall or photosynthetic pigments. This category of organisms is heterotrophs, meaning they eat food from the outside world (plants or animals). Their feeding mode is holozoic. To employ such a style of nutrition, they must eat, digest, absorb, and assimilate the food. This group of organisms can reproduce sexually or asexually. The presence of sensory organs and a nervous system is the greatest distinguishing trait of this group of species.
Porifera includes sponges, Cnidaria includes jellyfish, Echinodermata includes starfish, Arthropoda includes insects, Mammals, Birds, and Amphibians.
Animalia is divided into two sub-categories:
- Vertebrates are animals with backbones.
- Invertebrates are animals without backbones.
Plantae
Plants belong to the kingdom Plantae, as the name implies. Eukaryotes and multicellular organisms with cellulose-based cell walls belong to this category. Photosynthetic pigments are also present, allowing them to prepare their food. As a result, they mostly exhibit the autotrophic method of nutrition. This group of organisms can reproduce sexually or asexually. Plants are also classified into two categories:
- Plants that bloom
- Plants that do not flower
Pollination is used by flowering plants to reproduce sexually, while vegetative propagation is used by non-flowering plants to reproduce asexually.
Ferns, mosses, flowering plants, and other plants are examples.
Fungi
Fungi are Eukaryotes that can be unicellular, multicellular, or filamentous. They have chitin and polysaccharide-based cell wall. They eat in a heterotrophic mode, which means they can’t create their food and must rely on outside sources. If you’ve ever seen a hairy growth on long-decomposing food or stale bread, this developing creature is nothing more than fungi. Some fungi are parasitic, and the majority of them are saprophytes, meaning they feed on dead or rotting substances. Some fungi have been discovered to live in symbiotic relationships with other creatures, such as plants or viruses. Fungi are an essential type of organism in the ecosystem because they aid in the decomposition of organic matter. Fungi are also used commercially in our daily lives. By spore development, fungi can reproduce sexually or asexually.
Mushrooms, yeasts, and other organisms are examples.
Kingdom Protista
This category includes eukaryotic and single-celled organisms, sometimes known as unicellular organisms. Heterotrophs and autotrophs are both types of protists. Autotrophs are pant protists. Algae, for example, Spirogyra, Euglena, and others. Heterotrophs include animals and fungus-like protists. Amoeba and Paramecium are two examples. For motility, certain Protists have flagella or cilia. Protists can reproduce asexually through binary fission, nucleus division, budding, and other mechanisms, or sexually through the creation of gametes.
Monera Kingdom
Kingdom Monera includes single-celled prokaryotic organisms having a cell wall. In contrast to other organisms, their cell wall is made up of a polysaccharide and protein combination rather than cellulose. They lack a cell membrane, Golgi apparatus, mitochondria, endoplasmic reticulum, and other cell organelles. The single organism in this group is bacteria. They are tiny in size and can be found in large numbers. Bacteria are the source of life and have evolved.
Kingdom Monera is further subdivided into a) Archaebacteria, which is the most basic and primitive form of bacteria capable of surviving in harsh environments. b) Eubacteria- Organisms without a membrane-bound nucleus are commonly discovered in vertebrate intestines and soil.
Bacterial types
Bacteria are classified into four types based on their morphology.
- Micrococcus are spherical or sphere-shaped bacteria. They can be found on the skin, soil, meat, and other surfaces. These bacteria are generally harmless and saprophytic. To develop and reproduce, they require oxygen.
- Staphylococcus- Are also sphere-shaped bacteria, but they are contagious in some circumstances and can cause serious health problems such as food poisoning, diarrhoea, and skin infections. They can be found on the skin, hair, and other surfaces as well. Even in the absence of oxygen, they can thrive and grow.
- Bacillus- Bacteria with a rod-like form. They develop endospores, which make them extremely tough. These are saprophytes that can be found in soil, water, and dust.
- Pseudomonas are rod-shaped bacteria as well. Pseudomonas can create exotoxins, which is why they attack people with weakened or suppressed immune systems. They rarely attack healthy people. They can be found in soil, on the skin, and in other places.
Conclusion
Organisms can be classified to make their characteristics more understandable. Only a few individuals of a given kingdom can be used to investigate the properties of creatures. It aids in the investigation of origins and the study of growth patterns, reproduction, structure, and survival requirements. The Five Kingdom System also distinguishes between unicellular and multicellular creatures. We’ve provided a comprehensive overview of the Five Kingdom Classification that might aid in study preparation and information acquisition.