DIVERSITY IN LIVING ORGANISMS: DIVERSITY IN LIVING ORGANISMS CLASS: IX SUBJECT: SCIENCE PREPARED BY : Tushar Joshi Why do we classify organisms: Why do we classify organisms There are variety of organisms around us. It is very difficult to know about each. Thus, we have to make groups or classes on the basis of some similarities or dissimilarities. It will help us to study them easily and systematically. Range of variation s in life forms: Range of variation s in life forms some organisms are too small to be seen with the microscope and other are as big as blue whale. In case of plants some are single celled other are tall like red wood tree.( 100m tall ) Some live for hundred years, some die within few days. Some live on land and other live in water. Basis of classification: Basis of classification Whether they are made of prokaryotic or eukaryotic cells. Whether the cells are living singly or organized into multicellular and thus complex organisms. Whether the cells a have cell wall or not. Whether they prepare their food or not. Classification and evolution : Classification and evolution The present day complex living organisms have evolved from the earlier simple forms due to the changes in their body designs over millions of years. The body designs of living organisms are gradually changing due to the changes in environment and the need to adapt themselves to the changes occuring in the environment. PowerPoint Presentation: Some groups of organisms having ancient body designs have not changed much during evolution and have simple forms and structure. These organisms are called ‘primitive or lower organisms’. Some organisms have acquired their body designs relatively recently and have complex forms and structure. These organisms are called ‘advanced or higher organisms’. The hierarchy of classification: The hierarchy of classification Biologist Ernst Haeckel (1894), Robert Whittaker (1959) and Carl Woese (1977) classified all the living organisms into five broad categories called kingdoms, They are: Monera Protista Fungi Plantae Animalia The Five Kingdom classification: : The Five Kingdom classification: Organisms Prokaryotes Eukaryotes Unicellular Multicellular Protista With cell wall Without cell wall Animalia Do not perform photosynthesis Able to perform photosynthesis Fungi Plantae Monera Scheme used for classification: Scheme used for classification The following scheme is used to write the classification by writing the sub-groups: Kingdom. Phylum (for animals) / division (for plants). Class. Order Family. Genus. Species. A species includes all organisms that are similar enough to breed and perpetuate. It is the smallest unit of classification. Monera : Monera Organisms do not have defined nucleus or organelles in their cells.(prokaryotic cells) They do not show multicellular body design.(unicellular) Nutrition either autotrophic or heterotrophic. Some of them have cell wall while some do not. Examples are: Bacteria, blue green algae (cyanobacteria), mycoplasma. PowerPoint Presentation: BACTERIA PowerPoint Presentation: CYANOBACTERIA PowerPoint Presentation: BLUE GREEN ALGAE PowerPoint Presentation: MYCOPLASMA Protista : Protista The organisms are unicellular and eukaryotic. Hair like cilia and whip like flagella are present for their locomotion. Nutrition autotrophic or heterotrophic. Example are: unicellular algae, diatoms, protozoan ( amoeba, paramecium ) PowerPoint Presentation: ALGAE PowerPoint Presentation: DIATOMS Fungi : Fungi Eukaryotic and heterotrophic. They may be saprophytic or parasitic. Many of them have the capacity to become multicellular organisms at a certain stages of lives. Presence of cell wall made up of a tough complex sugar called chitin. Some fungal species live symbiotically (lichens ). Non green plant. Unicellular (yeast) or multicellular (mould). Examples are: Penicillium, agaricus, aspergillus. PowerPoint Presentation: YEAST PowerPoint Presentation: AGARICUS PowerPoint Presentation: LICHENS plantae: plantae They are multicellular eukaryotes having cell walls. They use chlorophyll for photosynthesis. All green plants are included in this group. They are divided into five groups. They are : Thallophyta, Bryophyta, Pteridophyta, Gymnosperms and Angiosperms. PowerPoint Presentation: Animalia (Animals) They include all organisms which are multicellular , eukaryotes, without chlorophyll and cell walls. They are heterotrophs. They are divided into ten groups. They are: Porifera, Coelenterata, Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata, protochordata vertebrates. THALLOPHYTA: The plant body is just like thallus. There is no differentiation of root stem and leaf. Absence of vascular system. They are predominantly aquatic. Reproductive systems are single celled. Examples: Ulothrix, Cladophora, Spirogyra, Chara, Ulva, Nitella. THALLOPHYTA PowerPoint Presentation: ULOTHRIX PowerPoint Presentation: CLADOPHORA PowerPoint Presentation: CHARA Bryophyta : Bryophyta Simplest land plant. Called as amphibious. Plant body is flat and have no true leaves. Roots are absent but root like structures called rhizoids are present. Vascular system is absent. Sex organs are multicellular . Examples are: liverworts (Riccia), Hornworts (marchantia), mosses (Funaria ). PowerPoint Presentation: Moss PowerPoint Presentation: Marchantia PowerPoint Presentation: Riccia Pteridophyta : Pteridophyta Plant body is made up of stem, leaves and roots. Presence of vascular system. Multicellular reproductive system. They are commonly called ferns. Reproduction generally by means of spores which are present on the under side of the leaf. Examples are: Marselia, Psilotum, Ophioglossum, silver fern, Adiantum, Pteris, Lycopodium, Selaginella, Equisetum. PowerPoint Presentation: FERNS PowerPoint Presentation: MARSELIA Gymnosperms (Cryptogams): Gymnosperms (Cryptogams) The plants of this group bear naked seeds (gymno – means naked and sperma means seed). They are usually perennial, evergreen and woody. Reproductive organs in the form of cones. Vascular tissues present. But xylem lacks vessels and phloem lacks companion cells. E.g. Pines (Pinus), Cycas, Gnetum, Ginkgo, Ephedra etc. PowerPoint Presentation: PINUS PowerPoint Presentation: CYCAS PowerPoint Presentation: CYCAS Angiosperms (Phanerogams): Angiosperms (Phanerogams) The plants of this group bears covered seeds (angio – means covered and sperma – means seeds. They are also called flowering plants. The plant embryo in the seed have cotyledons. Angiosperms are divided into two groups on the basis of the number of cotyledons. Plants with seeds having single cotyledon are called monocots. E.g. rice, wheat, maize etc. Plants with seeds having two cotyledons are called dicots. E.g. green gram, peas, tamarind etc. DIFFERENCES BETWEEN MONOCOTYLEDON AND DICOTYLEDON: DIFFERENCES BETWEEN MONOCOTYLEDON AND DICOTYLEDON Monocotyledon Dicotyledon In the seeds the embryo bear one cotyledon. In the seeds embryo bear two cotyledons. Parallel venation. Reticulate venation. Adventitious root system. Tap root system. Flowers are generally. Flowers are generally pentamerous. E.g. Wheat, rice, maize, oat, barley etc. E.g. Pea, Moong, Gram, groundnut, etc. Differences between gymnosperm and angiosperm: Differences between gymnosperm and angiosperm Gymnosperm Angiosperm The seeds are naked i.e. not enclosed inside the fruit. The seeds are not naked they are enclosed inside the fruit. Reproductive organs are cones. Reproductive organs are flowers. Xylem lacks vessels. Xylem have vessels. Phloem lacks companion cell. Phloem have companion cell. Classification of plants:: Classification of plants: Plants Do not have differentiated body parts Have differentiated body parts Thallophyta Without vascular tissue Bryophyta Bear naked seeds Do not produce seeds (Cryptogams) Pteridophyta Produce seeds (Phanerogams) Gymnosperms Angiosperms Bear covered seeds With vascular tissue One cotyledon Two cotyledons Monocots Dicots Porifera: Porifera They are called pores bearing animals. Mostly marine but few are fresh water ( spongilla ). They may be vase like, rounded, sac like, branched etc. Multicellular but not organized into tissues. Cells are loosely arranged. Commonly called sponges. Many small pores are present all over the body surfaces which are called Ostia. There is a single large opening at the top which is called Osculum. Here Ostia work as mouth and osculum work as anus. PowerPoint Presentation: They possesses a canal system which circulates water, through which food and oxygen may enter. Respiration and excretion done by diffusion. Reproduction by budding or by formation of gemules Stationary ( sessile) i.e. attached to the substratum. Examples are: Sycon, Euplectella, Spongilla, Scypha, Euspongia etc. PowerPoint Presentation: SPONGILA PowerPoint Presentation: SYCON PowerPoint Presentation: EUPLECTELIA PowerPoint Presentation: Sponges Sycon Euplectelia Coelenterata : Coelenterata They are aquatic animals.( both fresh water and marine animals) but mostly marine. There is a cavity in the body (coelom). The body has two layers of cells – an outer layer and an inner layer. Some live in colonies (corals) and others are single ( solitary). Presence of radial symmetry i.e. body can be divided into equal halves by any plane passing through the centre. Presence of tentacles. Reproduction by both sexual and asexual means. E.g. Corals, Hydra, Jellyfish, Sea anemone etc. PowerPoint Presentation: CORALS PowerPoint Presentation: HYDRA PowerPoint Presentation: HYDRA PowerPoint Presentation: JELLY FISH PowerPoint Presentation: SEA ANEMONE PowerPoint Presentation: Corals Jellyfish Sea anemone Hydra Platy helminthes (Flatworms) : Platy helminthes (Flatworms) Mostly parasitic but few are free living (planaria). Body is dorsiventrally flat i.e. why called flat worm. Bilateral symmetry. Triploblastic. Hermaphrodite. Excretion takes place through flame cells. Nervous system well developed and primitive brain is also present. Examples are: Planaria, liver flukes, tape worm etc. PowerPoint Presentation: Planaria PowerPoint Presentation: Liverfluke PowerPoint Presentation: Tape worm PowerPoint Presentation: Planaria Liverfluke Tape worm Nematoda: Nematoda They have cylindrical body. The body is bilaterally symmetrical. Triploblastic. They do not have true body cavity i.e. pseudo coelom They have tissues but no real organs. They are parasitic and causes diseases. Unsegmented body. Sexes are separate. Digestive system have both mouth and anus. Microscopic to macroscopic. Examples are: ascaris, wuchereria PowerPoint Presentation: Ascaris PowerPoint Presentation: Wuchereria Annelida: Annelida Segmented worm. Present in moist soil, fresh water as well as sea water. Some are parasitic. Body is elongated cylindrical and segmented. Triploblastic. Bilateral symmetry, Presence of true coelom. Digestive system well developed. Body bear lateral appendages called setae or parapodia. Excretion by nephridia. Sexes may be separate or hermaphrodite. Examples are: Earthworm, leeches, nereis, aphrodite etc. PowerPoint Presentation: EARTH WORM PowerPoint Presentation: NEREIS PowerPoint Presentation: LEECH PowerPoint Presentation: EARTHWORM NEREIS LEECH Arthropoda (Joint legged): Arthropoda (Joint legged) Largest group of animals.. Present every where. They have bilaterally symmetrical body. The body is segmented and divided into cephalothorax and abdomen. Skeleton is in the form of exoskeleton and chitinous Open circulatory system The body cavity is reduced and filled with blood called haemocoel. They have jointed legs. Sexes are separate. Respiration by gills, tracheae, book lungs, etc. E.g. Prawn, Crab, Cockroach, Spider, Scorpion, Butterfly, Housefly, Centipede etc. PowerPoint Presentation: PRAWN PowerPoint Presentation: CRAB PowerPoint Presentation: COCKROACH PowerPoint Presentation: SPIDER PowerPoint Presentation: SCORPION PowerPoint Presentation: BUTTER FLY PowerPoint Presentation: HOUSE FLY PowerPoint Presentation: CENTIPEDE Mollusca : Mollusca They have bilateral symmetry. The coelomic cavity is reduced. Body is soft unsegmented or little segmentation. Body is divided into three distinct parts: head, ventral foot, and dorsal visceral mass. Outer calcareous shell is present to protect the body. Respiration by gills. Sexes are separate. They have open circulatory system. kidney like organs for excretion. They have feet for moving around. E.g. Snails, Mussels, Chiton, Octopus etc. PowerPoint Presentation: SNAIL ( PILA ) PowerPoint Presentation: MUSSEL ( UNIO ) PowerPoint Presentation: CHITON PowerPoint Presentation: OCTOPUS Echinodermata (Spiny skinned): Echinodermata (Spiny skinned) Body unsegmented. Body covered with calcareous spines. Radial symmetry in adult and bilateral symmetry in larvae. Sexes are separate. They are free living marine animals. They are triploblastic and have coelomic cavity. They have water filled tube feet which help in movement. E.g. Star fish, Sea urchin, Feather star, Sea cucumber etc. PowerPoint Presentation: STAR FISH PowerPoint Presentation: SEA URCHIN PowerPoint Presentation: FEATHER STAR PowerPoint Presentation: SEA CUCUMBER Protochordata : Protochordata They have bilateral symmetry and are triploblastic. The have coelomic cavity. The body is divided into three parts : proboscis, collar and trunk. Gills are present for respiration. Sexes are separate. Presence of notochord at least at some stages of life. Marine animals. E.g. Balanoglossus, Amphioxus, Herdemania etc. notochord: notochord Notochord is a long rod like support structure that runs along the back of the animals separating the nervous tissues from the gut. It provides a place for muscles to attach for easy movement. PowerPoint Presentation: BALANOGLOSSUS PowerPoint Presentation: AMPHIOXUS PowerPoint Presentation: HERDEMANIA Vertebrata (Vertebrates): Vertebrata (Vertebrates) They have vertebral column and internal skeleton. They have bilateral symmetry and are triploblastic. They have coelomic cavity. Their body is differentiated into tissues and organs. Their body consists of four regions – head, neck, trunk and tail. They have two pairs of fins or limbs. The respiration in aquatic forms is by gills and in land forms respiration is by lungs The sexes are separate. Vertebrates are grouped into five classes.They are: Pisces, Amphibia, Reptilia, Aves and Mammalia. Pisces (Fishes): Pisces (Fishes) They are fishes living in water ( fresh and marine water ). Their skin is covered with scales or plates. They respire using gills by utilizing dissolved oxygen in water. They have streamlined body and fins which help them to move in water. They are cold blooded and their heart has only two chambers. They lay eggs from which the young ones hatch out. Some fishes have skeleton made of cartilage like Sharks, Rays etc. Some have skeleton made of bones and cartilage like Tuna, Rohu etc. PowerPoint Presentation: DOG FISH ( SHARK ) TUNA PowerPoint Presentation: STING RAY PowerPoint Presentation: ELECTRIC RAY PowerPoint Presentation: ROHU Amphibia (Amphibians): Amphibia (Amphibians) They are found in land and water.( amphibious in nature) They do not have scales but have mucous glands on their skin. They are cold blooded and the heart is three chambered. Respiration is through gills or lungs. Fertilization external. They lay eggs in water ( oviparous ). E.g. Frogs, Toads, tree frog, Salamanders etc. PowerPoint Presentation: FROG PowerPoint Presentation: TOAD PowerPoint Presentation: TREE FROG ( HYLA ) PowerPoint Presentation: SALAMANDER Reptilia (Reptiles): Reptilia ( Reptiles) They have scales and breathe through lungs. They are cold blooded. Usually terrestrial and live in warmer regions. Limbs are present with five fingers. Most of them have three chambered heart but crocodiles have four chambered heart. They lay eggs with hard covering in water. E.g. Snakes, Turtles, Lizards, Crocodiles etc. PowerPoint Presentation: SNAKE PowerPoint Presentation: TURTLE PowerPoint Presentation: LIZARD PowerPoint Presentation: CROCODILE PowerPoint Presentation: FLYING LIZARD Aves (Birds): Aves (Birds) They are warm blooded animals. They have four chambered heart. They breathe through lungs. Body boat shaped. Jaws are modified into beak. Bones are hollow. Presence of flight muscles. Respiration through lungs. They have an outer covering of feathers. Their two fore limbs are modified into wings for flying. They lay eggs. E.g. Crow, sparrow, Pigeon, Duck, Stork, Ostrich, penguin, kiwi etc. PowerPoint Presentation: CROW PowerPoint Presentation: SPARROW PowerPoint Presentation: PIGEON PowerPoint Presentation: DUCK PowerPoint Presentation: STORK PowerPoint Presentation: OSTRICH PowerPoint Presentation: PENGUIN Mammalia (Mammals): Mammalia ( Mammals) They are warm blooded animals. They have four chambered heart. Two types of limbs with five fingers. Respiration by lungs. They have mammary glands for production of milk to nourish their young ones. Body covered with hairs. Presence of sweat glands and oil glands. Most of them give birth to their young ones. Some of them lay eggs (like Platypus and Echidna). E.g. Cat, Rat, Dog, Lion, Tiger, Whale, Bat, Humans etc. PowerPoint Presentation: CAT PowerPoint Presentation: DOG PowerPoint Presentation: RAT PowerPoint Presentation: LION PowerPoint Presentation: BAT PowerPoint Presentation: HUMAN BEINGS PowerPoint Presentation: PLATYPUS ECHIDNA PowerPoint Presentation: KANGAROO Nomenclature : Nomenclature All living organisms have been given scientific names which can be used to identify them anywhere in the world. The system of scientific naming organisms is called binomial nomenclature. The binomial nomenclature consists of two parts. The first part is the name of the genus and the second part is the name of the species. E.g. The scientific name of human beings is : Homo sapiens. Homo is the name of the genus and sapiens is the name of the species. Rules for nomenclature: Rules for nomenclature The name of the genus begins with a capital letter. The name of species begins with a small letter. When printed scientific name is given in italics. When hand written both genus and species should be underlined separately.