Question

Characteristics of 5 kingdom classification

Answer 1

Over thousands and millions of years, a bewildering variety of species has evolved on the earth. Classification of these organisms was a serious challenge for the biologists. Many researchers had come forward with different categories to classify living things. Among them, Ernst Haeckel (1894), Robert Whittaker (1959) and Carl Woese (1977) are few whose contributions are notable. Modern-day of taxonomy has accepted the five kingdom classification of R. H. Whittaker. The basis of his classification is cell structure, mode, and source of nutrition and body design. Monera, Protista, Fungi, Plantae, and Animalia are the five kingdoms which were introduced by Whittaker.

Let’s learn about kingdoms Monera, Protista, and Fungi.

Kingdom Monera

1. Kingdom Monera comprises of unicellular organisms with a prokaryotic cell organization.
2. They lack well-defined cell structures including the nucleus and other cell organelles.
3. Cyanobacteria, bacteria, and mycoplasma are few members of this kingdom.
4. The general characteristic features of Monerans are: some have cell walls while some do not, they have an autotrophic mode of nutrition i.e., they can synthesize food on their own while some other have a heterotrophic mode of nutrition.

Kingdom Protista

1. Protista includes unicellular eukaryotes.
2. Amoeba, protozoan, diatoms, euglena, algae, and paramecium are few members of this kingdom.
3. Like monerans, protists also include both autotrophic and heterotrophic mode of nutrition.
4. Some protists like protozoan possess appendages for locomotion such as cilia and flagella.
5. All members of Protista kingdom reproduce through an asexual mode of reproduction either through binary fission and spore formation.

Kingdom Fungi

1. Fungi are eukaryotic organisms.
2. They consist of both unicellular (e.g. Yeast, Molds) and multicellular (e.g. mushrooms) organisms.
3. Like plant cells, fungi have cell walls made up of a complex sugar called chitin. But they do not perform photosynthesis.
4. They have a heterotrophic mode of nutrition. Few species are saprophytes i.e., they feed on dead and decaying organic matters.
5. Some fungi are parasitic while some are symbionts. They can live in symbiotic relationship with algae like blue-green algae. These are called lichens

Animalia

Kingdom Animalia consists of all animals. The animal kingdom is the largest kingdom among the five kingdoms. Animals are multicellular eukaryotes. But they don’t have a cell wall or chlorophyll like plants. Hence, members of the animal kingdom have a heterotrophic mode of nutrition. Kingdom Animalia has been classified into 10 different subphylums based on their body design or differentiation.

Different subphylums of the animal kingdom are as follows:

• Porifera
• Coelenterata (Cnidaria)
• Platyhelminthes
• Nematoda
• Annelida
• Arthropoda
• Mollusca
• Echinodermata
• Protochordata
• Vertebrata

Plant Kingdom – Plantae

Plantae is the plant kingdom which includes all plants on the earth. They are multi-cellular eukaryotes. They consist of cell walls and chlorophyll. Plants are photosynthetic. Hence, they have an autotrophic mode of nutrition. The plant kingdom is a vast group; therefore, the kingdom is further classified into subgroups. Level of classification is based on the following three criteria:

• Plant body– whether the body has well-differentiated structures or not.
• Vascular system-whether the plant has vascular system for transportation of substances or not
• Seed formation– whether the plant bears flowers and seeds or not; if it does, then whether it is enclosed within fruits or not.

Considering all these factors, the plant kingdom has been divided into five subgroups. They are as follows:

1. Thallophyta
2. Bryophyta
3. Pteridophyta
4. Gymnosperms
5. Angiosperms