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CLASSIFICATION

CLASSIFICATION. 2 million species identified and named Estimated total number ---100 million. TAXANOMY: The branch of biology that deals with the classification of organisms. . EARLY EFFORTS IN CLASSIFICATION. Aristotle (Fourth century B.C. );

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CLASSIFICATION

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  1. CLASSIFICATION 2 million species identified and named Estimated total number ---100 million TAXANOMY: The branch of biology that deals with the classification of organisms.

  2. EARLY EFFORTS IN CLASSIFICATION Aristotle (Fourth century B.C. ); • grouped animals according to their physical features = empirical or artificial classification • not scientific • John Ray (1600’s) • was the first scientist to use the term species • Species is a natural group of similar organsims that interbreed (mating within the same species) in nature.

  3. BINOMIAL NOMENCLATURE • Carl von Linnaeus (1700s) • Swedish botanist • is the founder of modern taxonomy • grouped organisms according to their structural similarities • gave a two-word Latin name to each organism

  4. BINOMIAL NOMENCLATURE Linnaeus named each species with a genus name followed by a single descriptive name. Ex: Felis domesticus specific name that defines properties of the organism genus name species name

  5. BINOMIAL NOMENCLATURE Gammarus anatoliensis Rhinoderma darwinii

  6. BINOMIAL NOMENCLATURE Vipera barani Acanthodactylus harranensis

  7. BINOMIAL NOMENCLATURE Pinus nigra Pinus sylvestris

  8. TAXONOMIC CATEGORIES

  9. TAXONOMIC CATEGORIES Number of shared characteristics decrease Number of individuals decrease

  10. TAXONOMIC CATEGORIES

  11. CLASSIFICATION OF SOME ORGANISMS

  12. WHAT TO LOOK AT WHEN CLASSIFYING Classification is based on: • Homologous organs • Similarities in embryonic development • Similarities in protein and enzyme structure • Similarities in DNA • Fossil information • Cellular structure • Behavioral characters

  13. WHAT TO LOOK AT WHEN CLASSIFYING Homologous organs: • Organs which have similar internal structures, but different functions • They develop from the same embryonic origin

  14. Analogous organs: • Organs which have the same function but have different internal structures • They have different embryonic origins • Analogous structures are not used in classification

  15. SIX KINGDOMS

  16. VIRUSES • A virus is a noncellular particle made up of genetic material and protein that can invade living cells. • A typical virus is composed of a core nucleic acid surrounded by a protein coat called capsid. • Depending on the virus, the nucleic acid is either DNA or RNA, but never both.

  17. PROPERTIES OF A VIRUS They do not have a cytoplasm and metabolism. They may have several shape and size. They are composed of a protein coat (capsid) and a nucleic acid which can either be DNA or RNA.

  18. PROPERTIES OF A VIRUS Each virus can invade specific cells. They are not affected from antibiotics, but they are affected from physical and chemical treatments. They are obligate inner parasites. They have to be in a host cell in order to be living.

  19. PROPERTIES OF A VIRUS Viruses can be classified according to their host cells or nucleic material.

  20. VIRUSES T4 BACTERIOPHAGE

  21. LIFE CYCLES OF VIRUSES LYTIC CYCLE The viruses that invade living cells and then cause the cells lyse, or burst. LYSOGENIC CYCLE The virus does not reproduce and lyse its host cell right away. The DNA of of the virus enters the cell and is inserted into the DNA of the host cell.

  22. VIRUSES

  23. VIRUSES

  24. STAGES OF LYTIC CYCLE 1. The virus attaches to the surface of host cell by its tail fibers. 2. The virus then injects its DNA into the cell. 3. The DNA of the virus is integrated into the DNA of the host cell. 4. As the virus takes over, it uses the materials of the host cell to make thousands of copies of its own protein coat and DNA. 5. The DNA molecules are covered with protein coat and other parts of the new virus are assembled. 6. The infected cell bursts and relases viruses that will infect other cells.

  25. LYTIC CYCLE

  26. STAGES OF LYSOGENIC CYCLE • In lysogenic infection, the virus does not reproduce and lyse the host cell right away. Instead, the DNA of the virus enters the cell and is inserted into the DNA of the host cell. • Once inserted into the host cell’s DNA, the viral DNA is known as prophage. • The prophage may remain part of the DNA of the host cell for many generations. • Eventually, the DNA of the prophage will become active, remove itself from the host cell’s DNA and redirect the synthesis of new virus particles. So, the lytic cycles begins.

  27. LYSOGENIC CYCLE

  28. PROKARYOTES ARCHAEBACTERIA • They lack peptidoglycan cell wall. • Their membrane lipids are different. • Their DNA sequence is like those in eukaryotic organisms. • They live in extreme conditions. EUBACTERIA • They can be found everywhere. • Cell wall is made of peptidoglycan.

  29. ARCHAEBACTERIA Halophiles (Salt lovers) Thermophiles Methanogens

  30. EUBACTERIA Cyanobacteria (Blue-green bacteria) Streptococci

  31. GENERAL STRUCTURE OF PROKARYOTES • All have cytoplasm • They don’t have nucleus • All have cell walls • All have ribosomes • Some have flagella for active movement • Some have mesosomes for aerobic respiration • Pathogens have capsule

  32. CLASSIFICATION OF BACTERIA Bacteria can be classified according to their • shapes • oxygen needs • Gram staining • way of nutrition

  33. BACTERIA ACCORDING TO SHAPE • Bacilli (rod-shaped) • Cocci (sphere-shaped) • Spirilla (spiral-shaped) • Vibrios (comma-shaped)

  34. BACTERIA ACCORDING TO GRAM STAINING Gram (-) bacteria: Take pink color. Gram (+) bacteria: Take purple color.

  35. BACTERIA ACCORDING TO OXYGEN NEEDS • Obligate Anaerobes: They must live in places with almost no oxygen. Oxygen may poison them. • Obligate Aerobes: They require oxygen in order to survive. • Facultative Anaerobes: They don’t need oxygen, but they can survive in the presence of oxygen.

  36. BACTERIA ACCORDING TO NUTRITION Heterotrophs Autotrophs Parasites Chemoautotrophs Mutualists Photoautotrophs Saprophytes

  37. BACTERIA ACCORDING TO NUTRITION Heterotrophs (They do not produce their own food) Parasites Saprophytes Mutualists • They live on the leftovers of the dead bodies of animals and plants. • They convert organic molecules into inorganic molecules • They are important for egological balance • they do not have digestive enzymes, so they have to live in places where digested food is present. • Ex: human digestive tract, blood, cells • Some are pathogens • They live within organisms but provide them favorable conditions and dont harm them • Ex: bacteria in digestive tract of herbivores help them digest cellulose

  38. BACTERIA ACCORDING TO NUTRITION Autotrophs (They can produce their own food) Photoautotrophs Chemoautotrophs • they are photosynthetic • They have chlorophyll and other pigments to absorb light energy • Ex: cyanobacteria • they get energy needed to synthesize food molecules by oxidizing inorganic substances like sulphure, iron, hydrogen, nitrogen. • Ex: Sulfur bacteria

  39. PROTISTA • Represented by 20.000 species • “Any eukaryotic organism that is not a fungus, animal or plant” • Mostly unicellular, but there are multicellular examples • Can live in colonies, but there are no differentiated cells or tissues • They live in a watery environment, in salty oceans, and fresh water or in moist soil. • Can be autotroph, heterotroph or switch to both ways if necessary • Some of them live as parasites

  40. PROTISTA • They do not have cell walls • As they are eukaryotic organisms, they have a membrane-bounded nucleus containing the hereditary material • They reproduce mostly by binary fission.

  41. PROTISTA Protozoa (Animallike Protists) Algae (Plantlike Protists) Funguslike Protists Unicelllar algae Sarcodines Flagellata Multicellular algae Sporozoans Cilliates

  42. PROTISTA FLAGELLATA EX: Euglena

  43. PROTISTA SARCODİNA Ex: Ameba CILIATA Ex: Paramecium

  44. PROTISTA SPOROZOA ÖR: PLAZMODIUM

  45. AMOEBA • Under the microscope, the ameba appears as a transparent mass that constantly changes shape. • It has ever-changing extensions called pseudopods (falsefeet). • Ameba moves by falsefeet and also it uses them to obtain food. • They take in food by phagocytosis into a food vacuole. As the food is digested, the temporary food vacuole disappears. • There is also a contractile vacuole which pumps out excess water.

  46. PARAMECIUM • Lives mainly in quite or stagnate pools. • It has a protectice covering called pellicle. • It has short, hairlike projections called cillia for movement. • Food particles enter through oral groove. • Wastes are removed from anal pore. • It has two nuclei; one is micronucleus that is responsible for reproduction, the other one is macronucleus that is responsible for other metabolic activities. • It has contractile vacuole. Contractile vacuole

  47. EUGLENA They • are plant-like protists • live in ponds and streams • have flagella for movement • include chloroplasts • have eyespot to sense light

  48. FUNGI They • have filamentous structure • have multicellular and unicellular forms. • have chitin in their cell walls. • absorb their food from the environment or they are saprobes. • reproduce by spores • store glycogen • don’t have real roots • can live as parasites

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