Taxonomy Notes (PDF)

10/16/2023 Taxonomy Dr. Omar Ammar OBJECTIVES 1) know history of biological classification (binomial nomenclature& six kingdoms). 2) know classification system. 3) classify organ...

10/16/2023 Taxonomy Dr. Omar Ammar OBJECTIVES 1) know history of biological classification (binomial nomenclature& six kingdoms). 2) know classification system. 3) classify organisms on the basis of evolutionary relationships. 4) describe organisms belonging to kingdom Monera. 5) list subdivisions of kingdom Monera. 6) compare and contrast the characteristics of organisms belonging to Eubacteria and Archaebacteria. 1  10/16/2023 Taxonomy  Taxonomy is the grouping of species based on common ancestry  Taxonomy is the branch of Biology that deals with the Identification, Nomenclature, & Classification of organisms. Nomenclature: naming of organism Classification: ordering of organism into group History of Classification 1- Aristotle (384-322 BC) Classify animals according to: A- Their way of living, B- Their habitat, C- Presence or absence of blood, D- Their body parts, E- The type of food. 2  10/16/2023 History of Classification 2- John Ray (1628-1705) Define “species” A group of animals have similar morphological characters & can breed freely with each others to produce fertile offspring resemble their parents. 3- Carl Linnaeus (1707-1778) Classify the animals on the basis of structure and published the principles of the current classification scheme. Taxonomy A- He divided the animals into: seven taxonomic ranks Kingdom ‫المملكة‬ Phylum ‫الشعبة‬ Class ‫الطائفة‬ Order ‫الرتبة‬ Family ‫العائلة‬ Genus ‫الجنس‬ Species ‫النوع‬ 3  10/16/2023 Taxonomy B- He Established Binomial nomenclature i.e each species has composed of 2 words: First word is genus ‫اسم الجنس‬ Second word is species ‫اسم النوع‬ Two words written in italic letters E.x: Bufo regularis ‫ ضفدع‬- Musca domestica ‫ذبابة منزلية‬ C- Classification morphological, anatomical characters. Carolus Linnaeus Swedish Botanist ❑ Developed classification system based on physical features ❑ Many rules still used today ❑ Binomial Nomenclature: Is a system of giving every organism 2 names 1st word: Genus (broad) 2nd word: Species (specific) Example: Felis catus (House cat) Genus: Felis (cougars, lions, tigers, cheetahs, etc…) Species: catus 4  ‫‪10/16/2023‬‬ ‫مملكة الحيوان‬ ‫شعبة الحبليات‬ ‫طائفة الثدييات‬ ‫الفهد‬ ‫رتبة آكلة اللحوم‬ ‫عائلة السنوريات‬ ‫جنس النمور‬ ‫نمر‬ ‫مملكة الحيوان‬ ‫شعبة الحبليات‬ ‫ذئب احمر‬ ‫طائفة الثدييات‬ ‫رتبة آكلة اللحوم‬ ‫عائلة الكلبيات‬ ‫جنس الكلب‬ ‫نوع الثعلبيات‬ ‫‪5‬‬  ‫‪10/16/2023‬‬ ‫مملكة حيوان‬ ‫شعبة الحبليات‬ ‫طائفة الثدييات‬ ‫رتبة‬ ‫الرئيسيات‪-‬الحيوانات‬ ‫عائلة‬ ‫البشرانيات أو القردة العليا‬ ‫جنس البشر‬ ‫نوع العاقل‬ ‫مملكة حيوان‬ ‫شعبة الحبليات‬ ‫طائفة الثدييات‬ ‫رتبة‬ ‫الحيتانيات‬ ‫عائلة الدلفين المحيطي‬ ‫جنس الحوت القاتل‬ ‫نوع الحوت القاتل‬ ‫‪6‬‬  10/16/2023 Common characteristics used for comparison among living organisms: 1. Cell type: Prokaryotes vs. Eukaryotes 2. Cell wall: Presence vs. Absence 3. Body type: Unicellular vs. Multicellular 4. Nutrition: Autotrophic vs. Heterotrophic 5. Reproduction: Sexual vs. Asexual Autotroph: is an organism that can Heterotroph: is an organism that eats other produce its own food using light, water, plants or animals for energy and nutrients. carbon dioxide, or other chemicals Differences between prokaryotes and eukaryotes Prokaryotes Eukaryotes Nuclear Absent Present membrane One copy Chromosomal N. Two copies (Diploid) (Haploid) Ribosome 70 S 80 S Mitosis Absent Present Cell wall Peptidoglycan Absent Examples Bacteria, viruses Fungi S value = Svedberg unit. 7  10/16/2023 The 5-Kingdom Classification System ❑ Scientists classified and organized the diverse species found on Earth into groups, such as kingdoms. One of these organizing efforts was done by Robert Whittaker in 1969, where he classified all living organisms into 5 kingdoms: The 5 Kingdoms 1) Kingdom Monera 2) Kingdom Protista 3) Kingdom Fungi 4) Kingdom Plantae 5) Kingdom Animalia Kingdom Monera ❑ Kingdom Monera can be subdivided into Archaebacteria and Eubacteria. Similarities between Archaebacteria and Eubacteria: 1) They are unicellular. 2) They lack a membrane-bound nucleus. 3) They reproduce asexually by binary fission. 8  10/16/2023 Kingdom Monera Differences between Archaebacteria and Eubacteria: Eubacteria are found in almost every environment on Earth, from marine ecosystems to forests to inside the human body. Archaebacteria are found in extreme environments. These environments include volcanic hot springs that can reach temperatures of above 90°C or bodies of water that have very high salt levels. Peptidoglycan is a major component of cell walls of Eubacteria, unlike Archaebacteria. Most of the protein-coding genes in prokaryotes are not interrupted with introns, but some of these genes in Archaebacteria have introns. Kingdom Monera Similarities and Differences between Subdivisions of Kingdom Monera 9  10/16/2023 Some recent findings …. ❑ In 1996, scientists decided to split Monera into two groups of bacteria: Archaebacteria and Eubacteria ❑ Because these two groups of bacteria were different in many ways. ❑ Scientists created a new level of classification called a DOMAIN ❑ Now we have 3 domains: 1) Bacteria 2) Archaea 3) Eukarya Taxonomy Life’s three domains: ❑ Scientists use taxonomy to name and classify organisms. ❑ The tree of life includes three main branches (domains). Domain: is the most general category of living things. All forms of life can be broadly categorized as either: 1) Domain Bacteria: unicellular prokaryote 2) Domain Archaea: unicellular prokaryote 3) Domain Eukarya: unicellular and multicellular eukaryotes 10  10/16/2023 Taxonomy Life’s three domains: Domain Eukarya: - Four kingdoms: Protista, Plantae, Fungi, and Animalia Living Things Living Things Domains Archaea Bacteria Eukarya Kingdoms Protists Fungi Plants Animals 11  10/16/2023 Compare Domains Living Things Domain Domain Domain Archaea Bacteria Eukarya Prokaryote Prokaryote Eukaryote Unicellular only Unicellular only Uni- or Multicellular No nucleus No nucleus Has a nucleus Found in extreme environments Found everywhere Found everywhere Cell wall Includes four Kingdoms Life’s three domains: Bacteria and Archaea ❑ Domains are divided into kingdoms. ❑ All three domains include one or more kingdoms, representing thousands to millions of different species. ❑ Domains Bacteria and Archaea consist of small, prokaryotic and unicellular organisms. ❑ Archaea domain holds the oldest known living things. 12  10/16/2023 Life’s three domains: Eukarya, Protista ❑ Organisms in Domain Eukarya have larger, more complex cells with nuclei. ❑ Protists are the most diverse group of eukaryotes, with multiple lineages, including amoebas, slime molds, algae, and other species. Autotroph: is an organism that can produce its own food using light, water, carbon dioxide, or other chemicals Heterotroph: is an organism that eats other plants or animals for energy and nutrients. Life’s three domains: Eukarya, kingdom Animalia Animals are a familiar group of eukaryotes, including vertebrates such as fish, frogs, and mammals, as well as invertebrates such as this bee. Humans belong to Eukarya domain 13  10/16/2023 Life’s three domains: Eukarya, kingdom Fungi Fungi are nature’s decomposers. Most are multicellular, like this mushroom; many are microscopic and unicellular, like yeast. Decomposers: (fungi, bacteria, invertebrates such as worms and insects) have the ability to break down dead organisms into smaller particles and create new compounds. Life’s three domains: Eukarya, kingdom Plantae ❑ Plants are producers that capture light energy from the sun. ❑ Energy from plants is passed to consumers and decomposers. ❖ Producers: are living things that can make their own food using air, light, soil, and water. ❖ Producer: is an autotroph. ❖ Autotroph: is an organism that can produce its own food using light, water, carbon dioxide, or other chemicals 14  10/16/2023 Life’s three domains: Eukarya, kingdom Plantae ❖ Consumer: is a living organism that eats organisms from a different population. ❖ Consumer: is a heterotroph ❖ Heterotroph: is an organism that eats other plants or animals for energy and nutrients. ❖ Decomposers: (fungi, bacteria, invertebrates such as worms and insects) have the ability to break down dead organisms into smaller particles and create new compounds. Question How are eukaryotes different from prokaryotes? A. Eukaryotes are always multicellular. B. Prokaryotic cells never have nuclei. C. Only prokaryotes are autotrophs. D. Only eukaryotes are living organisms. E. None of these distinguish eukaryotes from prokaryotes. 15  10/16/2023 Question How are eukaryotes different from prokaryotes? B. Prokaryotic cells never have nuclei. 16