2Basis of Classification Why do we classify things?* Classification provides scientists and students a way to sort and group organisms for easier study. * There are millions of organisms on the earth! (approximately 1.5 million have been already named)Organisms are classified by their: * physical structure (how they look) * evolutionary relationships * embryonic similarities (embryos) * genetic similarities (DNA) * biochemical similarities
4e.g. Spirulina, Oscillatoria. (1) Nucleus : (a) Organisms of this kingdom do not possess a well-developed nucleus. (b) Nucleolus and nuclear membrane are absent. (c) The genetic material occurs in the form of a mass of nucleoproteins.(2) Organelles of cytoplasm :Membranous organelles are also absent in the cell.(3) Types : Bacteria are the sole members of the kingdom Monera. This kingdom is divided into two divisions.(a) Schizophyta or Bacteria, (b) Cyanophyta (4)Nutrition: Bacteria live mainly as transformers, decomposers and also as parasites, e.g. E.coli Cyanophyta are also known as blue-green algae or cyanobacteria. They are autotrophic and posses photosynthetic pigments.e.g. Spirulina, Oscillatoria.
6(1) Structure : Organisms are unicellular or multicellular. (2) Nucleus : They possess a well developed nucleus.(3) Organelles : Membranous organelles like mitochodria, golgibody etc. are present. They do not exhibit division of labor.(4) Method of nutrition : They are autotrophic, heterotrophic and symbiotic methods of nutritions. Accordingly, protista are classified into autotrophs, phagotrophs or heterotrophs and symbionts.e.g. Algae, Protozoa and Fungi.
8(1) Cellwall : It is made up of chitin and cellulose or chitin. (2) Organelles : Mitochondria with flat cristae, organelles like lomasomes which are responsible for chemical constitution or Cellwall and Scattered ribosomes are representative characters of fungi.
9The fungal cell wall is composed of glucans and chitin (3) Nutrition : They exhibit saprophytic or parasitic mode of nutrition.(4) Body organization : Their body is called mycelium and the filament – like structures are called hyphae. (singular : hypha)(5) Example : Yeast, mucor.
10The chart given below briefly outlines the classification of The plant kingdom
11The Animal Kingdom is divided in several phyla mainly on the basis of the cell organisation, symmetry, presence or absence of notochord and body cavity. Animals are arranged progressively from simple single-celled protozoans to highly complex mammals. Given below are some of the main characteristics of each phyla.
13The simplest multicellular animals The simplest multicellular animals. The cells are loosely held together and do not form tissuesAquatic in habitat (mostly marine)The body is covered with poresFood and oxygen enter the organism along with water into a canal systemThey are non-motile animals attached to some solid supportReproduction may be sexual, asexual or buddingExample: Sycon, Spongilla, Euptectella
15Colentrates show more body desigh differentiation These animals live in waterColentrates show more body desigh differentiationThe body is made up of two layers of cells- one makes up cells on the outside and other makes the inner lining of the bodySome of the species live in colonies(corals) while others have a solitary life-spanE.g. Sea anemone, Jellyfish
17Simplest triploblastic organisms showing bilateral symmetry Mostly parasites in other animalsBody in dorsoventrally flat and leaf-like or ribbon-like with bilateral symmetryThe body cavity has only one opening which serves as both the mouth and the anusExample: Planaria, Liver Fluke, Tape Worm
19Triploblastic body showing bilateral symmetry Parasitic or free livingBody is long, smooth and cylindricalAlimentary canal begins with the mouth and ends with the anusExample: Ascaris (Round worm), Enterobius (Pinworm)
21)These animals are found in a variety of habitats- fresh water, marine water as well as landThey are bilaterally symmetrical, triploblastic animalsAnnelids are the first animals with true body cavityThey have metameric segmentation with extensive body differentiationE.g. Earthworm, Leech
23This is the largest phylum with almost 80% of the animal kingdom Body is bilaterally symmetrical and segmented. It is divided into head, thorax and abdomenPossess jointed legs which may be modified for walking, swimming feeding and feelingThe coelomic cavity is blood-filledOpen circulatory system is presentE.g. Prawn, Butterfly, Spider, Mosquito
25Aquatic in habitat but some land forms are also seen Bilateral symmetry is presentThe coelomic cavity is reduced and there is little segmentationOpen circulatory system is present and kidney-like organs for excretionThe soft body is supported by a hard shellLocomotion is brought about with muscular footE.g. Octopus, Pila
27Marine in habitatBody is triploblastic and has a coelomic cavityThey have a peculiar water-driven tube system for locomotionSkeleton is made of hard calcium carbonate structuresE.g. Star fish, Sea cucumber
31Sub-phylum Vertebrata This includes the majority of chordatesHead is prominentNervous system and exoskeleton are highly developedNotochord is replaced by a jointed vertebral columnTwo pairs of appendages (limbs)Aquatic animals have gillsVertebrates are grouped into five classes:Pisces, Amphibia, Reptilia, Aves and Mammalia
33These are fishes and exclusively water living animals The body is covered with scalesBody - streamlinedFins – present, limbs -absentMuscle tails is present which is used for movementRespiration through gillsCold-blooded, two chambered heartegg laying.
34They are two types based on The nature of their skeletons: 1) Cartilaginous fish- Their skeleton is made of cartilage such as sharks, rays etc.
352) Bony fish- Their skeleton is made of bones such as Rohu, Seahorse etc.
37Live in both water and on land Respiration is by gills, lungs or skin3 chambered heartIs cold bloodedHave two pairs of pentadactyl (5 digit) limbs which may be absent in some casesThey lay eggsE.g. Frog, Salamanders
39Mostly terrestrialHeart is 3 chambered, is cold bloodedBreathe through lungsBody covered with scalesHave two pairs of pentadactyl (five digit) limbs which are absent in snakesThey lay eggsThe heart is three-chamberedE.g. Snakes, Lizards, Crocodiles.
41Arboreal in habitat i.e., they live on trees Warm blooded. 4 chambered heartBody covered with feathersLungs have membranous extensions called air sacs to make the body lightMouth is surrounded by a beak. Teeth are absentFore-limbs are modified into wingsE.g. Sparrow, Pigeon
43Most intelligent of all organisms Warm blooded with 4 chambered heartGive birth to young onesThe mother suckles her young ones on milk secreted by special glands called mammary glandsBody covered with hairHave two pairs of pentadactyl limbsBreathe through lungsE.g. Humans, Whales, Elephant
44NomenclatureCarl Linnaeus, father of modern botany, was a Swedish naturalist who laid the foundation of modern classification and nomenclature in He devised a binomial system of nomenclature (naming system) in which an organism is given two names:A generic name (name of genus) which it shares with other closely related organisms which has features similar enough to place them in the same group.A specific name (name of species) which distinguishes the organism from all other species. No other organism can have the same combination of genus and species.The scientific name derived by using the system of nomenclature is followed all over the world as they are guided by a set of rules stated in the International Code of Nomenclature
45The scientific name derived by using the system of nomenclature is followed all over the world as they are guided by a set of rules stated in the International Code of Nomenclature.E.g. Mango (Mangifera indica)Tiger (Panthera tigris)