CLASSIFICATION • Two Kingdom Classification of organisms was proposed by Carolus Linnaeus in the year 1758. • He classified all living things into two kingdoms, they are Animal kingdom and Plant kingdom. • He named for animal kingdom as Regnum Animale(Kingdom Animalia) and plant kingdom as Regnum vegetable ( Kingdom Plantae) • This two kingdom classification laid the base for modern classification. • In his classification, he has distinguished clearly animals from plants.

• Carl Linnaeus - (23 May 1707 – 10 January 1778), also known after his ennoblement as Carl von Linné was a Swedish botanist, physician, and zoologist, who formalised the modern system of naming organisms called binomial nomenclature. • He is known by the epithet "father of modern taxonomy“ • Many of his writings were in Latin and his name is rendered in Latin as Carolus Linnæus. • Kingdom Plantae • The plant kingdom includes green plants, mosses, ferns, many colorless and colour unicellular organisms, molds, fungi, lichens, bacteria and multicellular seaweeds. The few distinguishing characters of plants. • Plants vary greatly in form and size. • The body is usually asymmetrical. • In higher forms of plants structures like leaves , flowers etc are present. • and plants have a definite shape and form. • Plants do not have the capability to move and they are fixed with root in the soil. • But few localized movements may occur in plants. • There is a continuous growth in their lifespan. • Plants’ nutrition is autotrophic or saprophytic. Minerals are absorbed in solution state by roots • will not absorb the particulate matter. • The plants body is having a distinct cell wall. • The plant cells have a vacuole filled with sap and plastids of different kinds. • Centrioles and lysosomes are absent in plant cell. • The reserve food in plants are in starch form. • Kingdom Animalia • Kingdom Animalia including multicellular organisms and unicellular protozoans. • These organisms have no chlorophyll and photosynthetic capability. • This is including protozoans, sponges, jellyfish, worms, crabs, insects, spiders, frogs, Snails, sharks, bony fishes, lizards, birds, and mammals. The distinguishing characters of animal as follows

• The animals show a definite shape, form and symmetry. • Animals are capable of moving from one place to another place. • The growth of the animal occurs proportionately in all body parts. • They respond to stimulus. • Animal body is made up of cells but without the cell wall. • Plastids and vacuoles are absent. • Centrosomes and lysosomes are present. • In animals, food is reserved in the form of glycogen. Demerits of Two kingdom classification

• This system is not suitable as due to a large diversity of among the organisms. • The main demerits are as follows • Euglena possesses characters of both plants and animals and they are not classified in a particular group. • both photosynthetic and nonphotosynthetic organisms are placed together. • Lichens are not included either in plant kingdom nor animal kingdom. • Euglena and Chlamydomonas having characters of both animals and plants. • So they can belong to any kingdom. Phylogenetic Classification by Eichler • August Wilhelm Eichler, also known under his Latinized name, Augustus Guilielmus Eichler (22 April 1839 – 2 March 1887), was a German botanist who developed a new system of classification of plants to reflect the concept of evolution. • His author abbreviation in botany is Eichler. • Based on the system of classification proposed by A.W.EICHLER(1875 - 78) , the plant kingdom is divided into two sub - kingdoms . • They are : 1. Cryptogamae . 2. Phanerogamae. • CRYPTOGAMAE (cryptogams)

• The cryptogams are flowerless (non- flowering)and seedless , spore bearing plants . • This sub-kingdom is sub-divided into three divisions:

(a) Thallophyta (b) Bryophyta (c) Pteridophyta • A. THALLOPHYTA (thallophytes): Thallophyta is the most primitive and the largest division of Cryptogams. • The plant body is not differentiated into root , stem and leaves and such a plant body is termed as thallus • The thalloid plant body is either unicellular or multicellular.

• The division thallophyta is classified into two sub - divitions: (1) Algae and (2) Fungi • 1. ALGAE Alage are chlorophyll bearing thalloid , autotrophic and largely aquatic (fresh water and marine water) plants . • They also occur in a variety of other habitats:- moist stones ,soils wood etc. Eg. Spirogyra . • 2. FUNGI Fungi are achlorophyllous (non-green) heterotrophic thallophytes . • They live as heterotrphs • Some fungi grown in close association with roots o f vascular plants forming mycorrhizae.

• Eg. Rhizopus • B . BRYOPHTA(Bryophytes): Bryophytes are chlophytes are are chlorophyllous , autotrophic, embryophic and atracheophytic cryptogams. • They are mostly found on damp and shady places. • They are called amphibians of plant kingdom. Eg. Funaria. • C.PTERIDOPHYTA(pteridophytes): Pteridophy tes are chlorophyllous, autotrophic embryophytic and tracheophytic cryptogams. • They are the non flowering plants possesing vascular tissues . • Hence they are called VASCULAR CRYPTOGAMS. Eg:pteris. 2. PHANEROGAMAE(phanerogams) Phanerogams are flower bearing ,seed producing tracheoptytes . • This sub kingdom has only one division SPERMATOPHYTA. • And 2 subdivisions: 1) Gymnospermae and 2) Angiospermae 1) GYMNOSPERMAE (gymnosperms): Gymnosperms are phanerogams or spermatophytes without ovary and fruit . The seeds are naked without a fruit wall. Eg: Cycas , Pinus 2) ANGIOSPERMAE(angiosperms):Angiosperms are the flowering plants in which the seeds are enclosed by fruits. • The angiosperms are divided into two classes : the dicotyledons and the monocotylesons . • Dicotyledons : They have two cotyledon in their seeds - Pea

• Monocotyledons- with single cotyledon exampel: Maize , sorghum ,etc R.H Whittaker- 5 Kingdom classification

• Organisms are divided into five major kingdoms. • R.H Whittaker proposed the five kingdom classification in 1969. • The most common system of classification in use today is the Five Kingdom Classification. • In this system all living organisms are divided into five kingdoms: • KINGDOM: MONERA • Kingdom Monera - It consists of primitive organisms. • The organisms are very small and single celled. • They consists of prokarytotes which includes species like the bacteria, archaebacteria, cyanobacteria and mycoplasma.

Example: bacteria. • KINGDOM: PROTISTA • Protista are single-celled eukaryotes and are mainly aquatic. • It includes diatoms, golden algae, euglena and protozoans like amoeba, paramaecium, plasmodium etc. • They are mostly marine and photosynthetic. • Example: Paramaecium • KINGDOM: MYCOTA • Kingdom Mycota or Kingdom Fungi consists of network of thread-like structures called as mycelium. • The bodies consists of long, thread-like structures which are called hyphae. • These organisms are mostly saprophytes or parasites and also symbionts. • This kingdom of fungi also includes lichens, mycorrhiza, etc. • Example: Aspergillus • KINGDOM: METAPHYTA • Kingdom Metaphyta or Kingdom Plantae are eukaryotic, mutlicellular plants, • They contain chlororphyll pigment, which helps them prepare their own food by the process of photosynthesis. • This kingdom includes all types of plants like herbs, shrubs, trees, flowering and non flowering plants. • Example: rose plant, mango tree, etc. • KINGDOM: METAZOA • Kingdom Animalia or Kingdom Metazoa are heterotrophic, eukaryotic, multicellular organisms. • They lack cell wall. • This kingdom includes all types of animals. • Example: Dog, cattle etc. Merits of Five kingdom classification

• Reveals course of evoloution • Plants and animals in this system are homogenous and judiciously separated • Prokaryotes are put in Monera- separate from higher plants- as they are morphologically and physiologically different from higher plants • Unicellular organisms are put under Protista- is appreciated as it avoids putting them either in plant kingdom or animal kingdom Demerits of Five Kingdom classification

• Monera and protista includes both photosyntheic and non photosynthetic groups • Evolution of some lower groups are not fully reflected. Eg. In green algae and certain photosynthetic bacteria, the source of hydogen for photosynthesis is not water- but they are placed in two different kingdoms. • Viruses, viroids and prions have no place in 5 kingdom classification Three domain, 6 kingdom classification • Carl Richard Woese - July 15, 1928 – December 30, 2012 • American microbiologist and bio physicist. • Woese is famous for defining the Archaea (a new domain of life) in 1977 by phylogenetic taxonomy of 16S ribosomal RNA, a technique pioneered by Woese which revolutionized the discipline of microbiology. • The Three Domain System, groups organisms primarily based on differences in ribosomal RNA (rRNA) structure. • Ribosomal RNA is a molecular building block for ribosomes. • Under this system, organisms are classified into three domains and six kingdoms. • The domains are Archaea, Bacteria, and Eukarya. • The kingdoms are : • Archaebacteria(ancient bacteria) • Eubacteria (true bacteria) • Protista • Fungi • Plantae • Animalia • Archaea Domain • This domain contains single-celled organisms known as archaea. • Archaea have genes that are similar to both bacteria and eukaryotes. • Like bacteria, Archaea are prokaryotic organisms and do not have a membrane bound nucleus. • They also lack internal cell organelles and many are about the same size as and similar in shape to bacteria. • Archaea reproduce by binary fission, have one circular chromosome, and use flagella to move around in their environment as do bacteria. • Archaea differ from bacteria in cell wall composition and differ from both bacteria and eukaryotes in membrane composition and rRNA type. • These differences are substantial enough to warrant that archaea have a separate domain. • Archaea are extreme organisms that live under some of the most extreme environmental conditions. • This includes within hydrothermal vents, acidic springs, and under Arctic ice. • Archaea are divided into three main phyla: Crenarchaeota, Euryarchaeota, and Korarchaeota. • Crenarchaeota include many organisms that are hyperthermophiles and thermoacidophiles. • These archaea thrive in environments with great temperature extremes (hyperthermophiles) and in extremely hot and acidic environments (thermoacidophiles). • Archaea known as methanogens are of the Euryarchaeota phylum. • They produce methane as a byproduct of metabolism and require an oxygen-free environment. • A Little is known about Korarchaeota archaea as a few species have been found living in places such as hot springs, hydrothermal vents, and obsidian pools (Solidified lava pools) • Bacteria Domain • Bacteria are classified under the Bacteria Domain. • These organisms are generally feared because some are pathogenic and capable of causing disease. • However, bacteria are essential to life as some are part of the human microbiota. • These bacteria perform vital functions, such as enabling us to properly digest and absorb nutrients from the foods we eat. • Bacteria that live on the skin prevent pathogenic microbes from colonizing the area and also aid in the activation of the immune system. • Bacteria are also important for the recycling of nutrients in the global ecosystem as they are primary decomposers • Bacteria have a unique cell wall composition and rRNA type. • They are grouped into five main categories: • Proteobacteria: This phylum contains the largest group of bacteria and includes E.coli, Salmonella, Heliobacter pylori, and Vibrio. bacteria. • Cyanobacteria: These bacteria are capable of photosynthesis. • They are also known as blue-green algae because of their colour. • Firmicutes: These gram-positive bacteria include Clostridium, Bacillus, and mycoplasmas (bacteria without cell walls). • Chlamydiae: These parasitic bacteria reproduce inside their host's cells. • Organisms include Chlamydia trachomatis (causes chlamydia STD) and Chlamydophila pneumoniae (causes pneumonia). • Spirochetes: These corkscrew-shaped bacteria exhibit a unique twisting motion. • Examples include Borrelia burgdorferi (cause Lyme disease) and Treponema pallidum (cause syphilis) • Eukarya Domain • The Eukarya domain includes eukaryotes, or organisms that have a membrane bound nucleus. • This domain is further subdivided into the kingdoms Protista, Fungi, Plantae, and Animalia. • Eukaryotes have rRNA that is distinct from bacteria and archaeans. • Plant and fungi organisms contain cell walls that are different in composition than bacteria. • Eukaryotic cells are typically resistant to antibacterial antibiotics. • Organisms in this domain include protists, fungi, plants, and animals. • Examples include algae, amoeba, fungi, molds, yeast, ferns, mosses, flowering plants, sponges, insects, and mammals.