Binomial classification

Transcription

1 Binomial classification

2 KEY CONCEPT Organisms can be classified based on physical similarities.

3 Why do we classify living Organisms? To make this great biodiversity easier to study!

4 Classification is the grouping of organisms based on similarities of features. Taxonomy is the science of studying classification. It looks at features and tries to arrange them in a logical order.

5 Two main types of classification Artificial classification: in which easily observable characteristics are used. such as colour, mode of locomotion, habitat etc Natural classification: which reflects possible evolutionary relationships, based on ancestry (phylogeny)

6 Early Classification Aristotle (384 to 322 BC) Greek Scholar Divided animals into three groups Those that fly Those that swim Those that crawl or walk

7 Linnaean Classification System Developed in the mid 1700 s by Swedish botanist named Carolus Linnaeus. Classifies all organisms as animals or vegetable (plant) Gave all organisms a two part Latin name.

8 Why did Carolus Linnaeus develop this system? The yellow and white flower with many small petals The yellow and white flower with no obvious scent Carl Linnaeus Chrysanthemum leucanthemum The pretty flower with a fuzzy yellow center surrounded by white petals which attracts small bees.

9 How it s organized Linnaean classification system has seven levels. Each level is included in the level above it Levels get increasingly specific from kingdom to species.

10 A taxon (taxa plural) is a group of organisms in a classification system. A species is the fundamental taxon Groups of similar species form the next largest taxon called a genus. Groups of similar genera form the next largest taxon called a family and so on, up to the largest taxon = Kingdom.

11 Seven Levels of classification 1. Kingdom 2. Phylum 3. Class 4. Order 5. Family 6. Genus 7. Species King Phillip Called Others From Germany, Singapore.

12 Limitations of Linnaean Classification Physical similarities are not always a result of a species being closely related Unrelated species can evolve similar traits. Modern classifications uses genetic similarities.

13 Recent DNA research has changed some long standing classifications.

14 Binomial nomenclature A naming system that gives each species a unique two part name. Uses Latin and Greek words. Uses the Genus and Species as first and last name. White oak: Quercus alba

15 Advantages over common names: Scientific names help scientists to communicate. Some species have very similar common names. Some species have many common names.

16 Genus - includes one or more physically similar species that are closely related. Always written in italics and Capitalized Species a group of organisms that can successfully breed and produce offspring. Always written in italics and lowercase Tyto alba

17 Binomial Nomenclature Family Family Felidae (Cats) Tiger - Panthera tigris Lion - Panthera leo Kitten Felis domesticus Cougar Felis concolor Genus and species are always italicized OR underlined if hand written First letter of the genus is capitalized First letter of the species is lowercase

18 Let's try some simple naming - Latin The brown caterpillar Noun first descriptor second. i.e. caterpillar brown Eruca castane

19 Let's try some simple naming - Greek The spotted reptile Herpeto halio

20 Let's try some simple naming - Greek Reptile with a flat nose. Herpeto platyrhino

21 Types of Invertebrates The invertebrates are a group of animals (and animallike organisms) that do not have a backbone. The group of invertebrates without specific organs is referred to as the lower invertebrates. For example, Protozoans and Porifera, while the higher developed invertebrates have a true coelom like mollusks, annelids, echinoderms, and arthropods. Generally, the invertebrates are divided into four groups, based on their cellular composition and organization, namely Protozoa, Mesozoa, Parazoa and Metazoa

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23 Protozoa They are for the most part of their lives unicellular, i.e. made up of one cell They are also described as being acellular i.e. not divided into cells (non-cellular). Their vital functions are carried out by organelles.

24 Mesozoa (Greek: mesos = middle; zoon = animal) The name was given because mesozoans are thought to be intermediate between true multicellular animals and protozoans (singlecelled/acellular organisms). Their bodies are cellular. They do not have more than two cell layers ; the outer layer ciliated and the inner reproductive.

25 Mesozoa They are bilaterally symmetrical. They have no organs. They have no body cavity. Gametes and agametes are produced from special cells, which form the central mass of the body.

26 Parazoa Multicellular invertebrates, which possess collared flagellated cells that make them unique among the other multicellular invertebrates. The many cells in their body are not organized into tissues and organs. They are therefore at the cellular level of organization.

27 Metazoa Invertebrates with marked cellular differentiation. There are two levels of organization in this group: Diploblastic includes animals with two cell layers showing tissue level of organization, where the body is composed of an inner endoderm and outer ectoderm. Triploblastic includes animals with three layers showing organ level of organization; they possess a third body layer, the mesoderm between the outer ectoderm and inner endoderm.

28 Characteristic features of Protozoa 1. SMALL, MICROSCOPIC. 2. PROTOPLASMIC GRADE OF ORGANIZATION. 3. UNICELLULAR, MULTINUCLEATED (MONOMORPHIC OR DIMORPHIC). 4. SOLITARY, FORMING LOOS COLONY. 5. SYMMETRY NONE

29 Characteristic features of Protozoa 6. SUBCELLULAR PHYSIOLOGICAL DIVISION OF LABOUR. 7. LOCOMOTION BY LOCOMOTORY ORGANS LIKE CILLIA,FLAGELLA OR THROUGH PSEUDOPODIA. 8. NUTRITION HOLOZOIC OR HOLOPHYTIC OR PARASITIC OR SAPROZOIC

30 DIGESTION

31 9. DIGESTION : INTRACELLULAR THROUGH FOOD VACUOLES. 10. RESPIRATION AND EXCRETION: THROUGH GENERAL BODY SURFACE OR TROUGH CONTRACTILE VACUOLES. 11. REPRODUCTION ASEXUAL BINARY OR MULTIPLE FISSION. SEXUAL CONJUGATION ENCYSTMENT MAY BE.

32 Classification of the Protozoans They are broadly divided into four subphyla based mainly on their organelles and modes of locomotion as follows: Sub-Phylum: Sarcomastigophora Sub-Phylum: Sporozoa Sub- Phylum: Cnidospora Sub- Phylum: Ciliophora

33 SubPhylum Sarcomastigophora Uses flagella or pseudopodia as a means of locomotion. Ex Amoeba, Entamoeba, Euglina,Volvox single nucleus(monomorphic), Asexual reproduction is by longitudinal binary fission. A. Superclass MASTIGOPHORA B. Superclass OPALINATA C. Superclass SARCODINA

34 A. Superclass MASTIGOPHORA Body is covered by pellicle; locomotory organelles are flagella; Asexual reproduction by longitudinal binary fission. It includes two classes Phytomastigophora and Zoomastigophora

35 Superclass MASTIGOPHORA 1. Class Phytomastigophorea Some are with chlorophyll bearing chloroplasts Nutrition is holophytic Reserve food is paramylum Includes euglenoids and dinoflagllates 2. Class Zoomastigophorea Mostly parasitic; Chloroplasts are absent; nutrition is holozoic saprozoic or parasitic, Reserve food is glycogen or volutin.

36 Class Phytomastigophorea (Phytoflagellates): 6 orders Order 1. Cryptomonadida- Cryptomonas Order 2. Dinoflagellida- Noctiluca.

37 Class Phytomastigophorea Order 3. Euglenida - Euglena Order 4. Chrysomonadida - Dinobryon Order 5. Volvocida - Volvox Order 6. Chloromonadida - Chattonella

38 Class Zoomastigophorea (Zooflagellates)- 2 orders Order 1. Choanoflagellida Proterospongia Order 2. Kinetoplastida- Leishmania, Trypanosoma.

39 B. Superclass OPALINATA Commensals or parasites in the gut of anurans. Body is covered by oblique rows of cilia but without infraciliary system. Some are binucleate, others are multinucleate but homokaryotic. Examples Opalina

40 C. Superclass SARCODINA (=RHOZOPODA) Locomotion is brought about by pseudopodia. It includes three classes Rhizopodea Piroplasmea Actinopodea

41 Class Rhizopodea It includes amoebas, foraminiferans. Amoebas have lobopodia or filopodia Foraminiferans have reticulopodia. In amoebas body is soft. Foraminiferans have a calcareous porous shell.

42 Class Piroplasmea Parasitic; locomotory structures absent; spores are absent. Example: Babesia (causes red water fever in cattle)

43 Class Actinopodea These are the ray footed protozoans. Locomotory structures are axopodia. Skeleton consists of siliceous shell (Radiolaria) or strontium sulphate spines (Acantharea) or siliceous shell or radiating needles (Heliozoa). Silicious shells of radiolarians form ooze. Examples: Collozoum (radiolarian) Actinophrys (heliozoan) Acanthometra, Actinosphaerium

44 Sub-Phylum: Sporozoa Locomotory organs absent, spores usually present, endoparasitic) eg. Eimeria, Monocystis, Plasmodium It includes three classes - Telosporea, Toxoplasmea and Haplosporea.

45 Class: Telosporea Spores without polar capsules and filaments Sporozoites are long Subclass Gregarinea (Monocystis; Gregarina). Subclass Coccidia (Plasmodium).

46 Class: Haplosporea Spores are present and are amoeboid, Reproduction is only asexual, by multiple fission. Each spore contains singl e sporozoite o Example: Haplosporidium

47 Class: Toxoplasmea Body covered by two layered pellicle Only asexual reproduction, by endodyogeny. It is internal budding wherein two daughter cells are produced within a mother cell and the mother cell is destroyed in the process, Example: Toxoplasma

48 Sub- Phylum: Cnidospora Parasitic. No special locomotory structures. Spores are provided with one or more polar filaments, which are useful for attachment to the host. It includes two classes - Myxosporidea and Microsporidea

49 Sub- Phylum: Cnidospora Class Myxosporidea Extracellular parasites of cold blooded vertebrates. Spores with typically two capsules each with single polar filament. Example: Myxidium Class Microsporidea Intracellular parasites in fish. Spore with one intrasporal or 1-2 intracapsular filaments. Example: Nosema bombycis

50 Sub- Phylum: Ciliophora Complex protozoans. Cilia are useful in locomotion and food capture. Dimorphic nuclei - macronucleus (vegetative and polyploid) and micronucleus (reproductive and diploid), Sexual reproduction by conj ugation, which brings about nuclear reorganization. Only class under this subphylum is Class Ciliata. o Example: Paramecium, Balantidium.

51 Class Ciliata Balantidium). Subclass Holotricha (Paramecium; Subclass Peritricha (Vorticella). Subclass Suctoria (Ephelota; Podophrya). Subclass Spirotrichia (Stentor)

52 Class Ciliata Subclass Holotricha Buccal cillia absent. Body cillia simple and uniform. Orders- 6 1.Gymnostomatida 2.Trichostomatida (Balantidium) 3.Chonotricha 4.Apostomatida 5.Astomatida 6.Hymenostomatida (Paramecioum) Subclass Peritricha Adult wothout body cillia. Apical end with buccal cillia. Oreder Peritrichida (Vorticella)

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54 Subclass Suctoria Subclass Suctoria Sessile and stalked body. Young with cillia, adult with suctorial tentacle Order- Suctoria ex Podophyra Subclass Spirotrichia Reduced body cillia. Buccal cillia well marked. Ex Nyctotherus Orders- 3 Hetertrichida Oligotrichida Hypotrichida