Chapter 17 Notes Taxonomy THE USEFULNESS OF ORGANIZATION

Chapter 17 Notes, Taxonomy

THE USEFULNESS OF ORGANIZATION Have you ever heard your parents tell you to clean your room? Why do you suppose they told you to clean your room? If you went to the school's library to look for a book, where would you begin? Are all the books in the library randomly arranged without any rhyme or reason? Or is there a system of arrangement that allows you to find what you are looking for in the quickest way possible?

WOULD YOU RATHER TRY TO FIND SOMETHING HERE?

OR HERE?

WHY DO BIOLOGISTS ORGANIZE LIVING ORGANISMS? Biologists have named about 1. 7 million species (known) on our planet. There about than 62, 000 (known) vertebrate species on our planet. There about than 1, 300, 000 (known) invertebrates. There about than 320, 000 (known) species of plants on our planet. About 13, 000 new species are added per year. Not to mention all the species of bacteria, fungus, and protozoa that are found all over our entire planet.

WHAT IS TAXONOMY Taxonomy is the field of biology that explains how biologists organize, identify, name, and classify living organisms. In taxonomy, organisms are grouped into various groups called taxons. Taxons are classified by similarities and differences between organisms. The first and broadest taxon in taxonomy is called a domain. Domains are classified by cell type and cell structure.

WHAT ARE THREE DOMAINS IN BIOLOGY? Domain Bacteria – organisms that are prokaryotic, unicellular, and they have cell walls made of peptidoglycan. Bacteria can be aerobic or anaerobic. Bacteria are the most abundant living organisms on the planet. There are probably more bacteria in your own body than there are people in the world.

DOMAIN BACTERIA (ESCHERICHIA COLI) E. coli is one of the most common forms of bacteria found in the intestinal tract of warm -blooded animals (including humans). Most strains of E. coli are harmless, but some strains can cause severe food poisoning.

THREE DOMAINS IN BIOLOGY Domain Archaea – These bacteria used to be classified together with Domain Bacteria. Cell walls do not contain peptidoglycan. Unicellular like bacteria. Also called extremophiles, because they can live in extreme hostile environments. Examples of environments inhabited by bacteria in domain Archaea are hot springs, hypersaline lakes, and places with extreme depths, pressures and temperatures.

DOMAIN ARCHAEA (EXTREMOPHILES) These are examples of hostile environments occupied by extremophiles. Hot springs in Yellowstone National Park and hydrothermal vents giving off hydrogen sulfide.

THREE DOMAINS IN BIOLOGY Domain Eukarya – This domain includes all the living organisms that have cells with a membrane-bound nucleus and membranebound organelles. There are four smaller taxons called Kingdoms found in the domain Eukarya. These kingdoms are Kingdom Protista, Fungi, Plantae, and Animalia.

KINGDOMS IN EUKARYA Kingdom Protista – Protists can be unicellular, multicellular, or colonial. Protists can be autotrophic or heterotrophic. Protists have no organs or tissues. There are plant-like protists like algae and kelp. There animal-like protists like amoebas and paramecium. There are fungus-like protists like slime-molds and mildews. Even some like Euglena, which are protists with both plant-like and animal-like characteristics.

KINGDOM PROTISTA Protists are kind of like the oddball misfits of Eukarya that don't fit into any other kingdoms.

PLANT-LIKE PROTISTS Kelp and algae look like plants, but they are considered protists because they lack the complex tissues and organs that are found in plants.

ANIMAL-LIKE PROTISTS (PROTOZOA) Paramecium with cilia for locomotion. This animal-like protist is heterotrophic like an animal, but it is unicellular and lacks organs and tissues like true animals.

FUNGUS-LIKE PROTISTS Slime mold and mildew share a lot of characteristics with true fungi. Their cell walls do not contain chitin like true fungi.

KINGDOMS IN EUKARYA Kingdom Fungi – Organisms in this kingdom are both unicellular and multicellular. Fungi are heterotrophic, lack the ability to move, and have cell walls made of Chitin. Some fungi are parasitic, which means they grow and feed on other living organisms. Some fungi are saprobic, which means they eat dead or decaying organic matter. Fungi secrete digestive enzymes externally and absorb digested materials.

KINGDOM FUNGI Probably the most common and well known of all the fungi is the mushroom.

KINGDOMS IN EUKARYA Kingdom Plantae – All organisms in Kingdom Plantae are multicellular. All plants have cell walls made up of cellulose. Plants are autotrophic and they possess organelles called chloroplasts. All plants possess cells that are organized into tissues, and most plants possess organs such as roots, stems, and leaves. Plants lack the ability to move, with the exception of some reproductive cells that bear flagella that propel them through water.

KINGDOM PLANTAE Plants are the first organism we have discussed that have complex tissues and organs.

KINGDOMS IN EUKARYA Kingdom Animalia – Animals are heterotrophic, multicellular, and they do not have cell walls. Remember animal cells have a cell membrane. Most animal cells are organized into tissues , tissues are organized into organs, and organs are organized into organ systems. Most animals have the ability to move and some type of a nervous system (brain).

KINGDOM ANIMALIA

TAXONOMIC HEIRARCHY This is a simple acrostic or mnemonic to help remember the taxonomic hierarchy. King – Kingdom Peter – Phylum (Division for plants and bacteria) Came – Class Over – Order From – Family Germany – Genus Swimming - Species

TAXONOMIC HIERARCHY Using the example of the brown and black bear. Both are in the Kingdom Animalia because they are animals and not plants, fungi, bacteria etc. Both are in Phylum Chordata because they both have a vertebral column with a spinal cord. Both are in the Class Mammalia because they both have hair, mammary glands etc. Both are in the Order Carnivora because they consume meat and have carnivorous teeth. Both are in the Family Ursidae which includes all the bears found all over the world.

Taxonomic Hierarchy (Black Bear)

Taxonomic Hierarchy (Brown Bear)

TAXONOMIC HIERARCHY Both bears are in the Genus Ursus which also includes the Polar Bear (Ursus maritimus) and the Asiatic Black Bear (Ursus thibetanus). All of these bears are very closely related. The bears below are more distantly related to other bears in the family Ursidae so they are all place in their own separate genera. The Giant Panda Bear (genus Ailuropoda) The Sun Bear (genus Helarctos) The Sloth Bear (genus Melursus) The Spectacled Bear (genus Tremarctos)

Genus Ursus

Other Bears in Family Ursidae but not in Genus Ursus

HERE IS A COMPARISON WITH THE FELIDAE (CAT) FAMILY

TAXONOMIC HIERARCHY The last and most specific taxon is the species name or species epithet. Species refers to only one specific group of organisms that are a successfully reproducing population of organisms. Each species may have different common names, depending on the location, but it will always have only one species name. For example, Felis concolor has many different common names like the cougar, mountain lion, puma, mountain cat, catamount, or panther.

FELIS CONCOLOR

BINOMIAL NOMENCLATURE Species names are universal, so no matter where you travel around the world, the species name is always the same. Species names are also similar to our names. People have a first name and a last name. Your first name is more general (John, Sarah, Thomas etc. ). Your last name is more specific (Johnson, Smith etc. ). But when someone calls you by both your first name and last name it is more specific.

BINOMIAL NOMENCLATURE The first part of the species name is the Genus name. This name indicates which animals it is most closely related to. The second part of the name is the specific species epithet. For example Ursus americanus is scientific species name of the Black bear. Or Ursus arctos is the name for the Brown bear. Species can also have a third name, which is called a subspecies name. Like Ursus arctos horribilis the Grizzly bear, or Ursus arctos middendorfi the Brown bear.

IS THIS AN ELK OR MOOSE?

RULES OF BINOMIAL NOMENCLATURE When using proper binomial nomenclature, the Genus should be always be capitalized, and the species name, or specific species epithet should always be lowercase. When typed, the species name should be italicized. When writing species names by hand, the species name should always be underlined. If a species name is repeated when writing a paper or a scientific report, the genus may be abbreviated (F. concolor) after the first time it has been written.