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Classifying living things

Classifying living things. Scientists develop system for classifying living things. Scientists classify millions of species 400 years ago organisms were classified on their appearance and behavior The problem with this is scientists have realized that appearances can suggest false connections.

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Classifying living things

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  1. Classifying living things • Scientists develop system for classifying living things. • Scientists classify millions of species • 400 years ago organisms were classified on their appearance and behavior • The problem with this is scientists have realized that appearances can suggest false connections. • Many things helped change these classifications • Observing • Collecting samples • The microscope

  2. Classifying living things • Classification and Taxonomy • Classification is the process of arranging organisms into groups based on similarities • Taxonomy is the science of naming and classifying organisms. • A good system allows one to organize a large amount of information • so it is easy to find and understand.

  3. Classifying living things • Using Classification • Similarities and differences among species are used • Sometimes easy to see like fur, feathers, or scales • Others more detailed and require DNA • Taxonomists study Biological relationships • The Greek word, taxis means arrangement. • Taxonomists are scientists who classify and name organisms based on their similarities and differences.

  4. Classifying living things • A Taxon is a group of organisms that share certain traits. • Taxons can be broad like animals and plants • More specific like cats and roses. • Taxonomists try to discover how one species evolved as compared with another species. • Species sharing an ancestor are group together.

  5. Classifying living things • To determine how to classify, scientists compare a variety of characteristics or traits • A trait is a characteristic or behavior that can be used to tell two species apart. • IF two organisms share a trait, taxonomists try to determine if they share the trait because they share an ancestor.

  6. Classifying living things • Physical Evidence • All physical evidence helps scientists see that all living organisms are related by evolution • Primary tools used • Color • Size • Weight • How group of organisms obtain energy. • The internal structure • And outward appearance • Comparing skeletons, and fossilized parts

  7. Classifying living things • Genetic Evidence • In the mid 1950’s DNA helped further classify • Genetic evidence usually support physical evidence, but not always • Best example is the red panda and Panda bear • Both ate bamboo, • Both look alike except for size • DNA proved that the red panda is more related to the raccoon family • Pandas more closely to bears

  8. Classifying living things • Biologists use seven levels of classification • Carolus Linnaeus developed both a naming system and how to organize them. • Used appearance to group • This was called the binomial nomenclature. • Binomial means two names • Nomenclature means list of names • Most of these names are Latin

  9. Classifying living things • Using scientific names • He used both a genus and species. • Certain rules for scientific names must be followed • First letter of the genus (which comes first) is capitalized • Species’ first letter is lowercase • Both written in italics • These two names are part of a classification system that contains several larger parts.

  10. BINOMIAL NOMENCLATURE • Uses two names • A GENUS and A SPECIES • Haliaeetus leucocephalus • Genus is always CAPITALIZED • Species is always lower case • BOTH ARE IN ITALICS OR UNDERLINED • Just like us, each animal was given 2 names

  11. Canis latrans Coyote Canis lupis Timber Wolf Canis familiaris Domesticated Dog Panthera leo Lion Panthera onca Jaguar Latin Binomials

  12. Classifying living things • Classified into 7 groups • Each group gets narrower or specific then that last. • Kingdom (most general) (Animalia- the animals) • Phylum (Chordata- animals with a backbone) • Class ( Mammalia- mammals or furry animals that nurse their young.)

  13. Classifying living things • Order ( Carnivora- carnivores, or animals that kill and each other animals) • Family (Felidae- cat family) • Genus( Felis housecats, cougars, and many others • Species (catus- all housecats regardless of breed) • Scientists can compare very broad categories, • As they go down the classification level, you get more specific, eliminating organism that are not longer similar.

  14. Classifying living things • Dichotomous keys and field guides help identify • A series of questions that can be answered in only 2 ways • Your answer to each question leads to another question with only 2 choices • The questions gradually narrow down the list of possible organisms. • Field guides also help identify based on physical characteristics.

  15. Classifying living things • Classification systems change as more is learned. • Taxonomy changes as discoveries are made • First there were 2 groups • Plants • Green • Non-moving • Animals

  16. Classifying living things • Three Domains • Grouping before placing organism into Kingdoms • Cells containing a nucleus are called eukaryotic cells • Cells with no nucleus called prokaryotic cells • The domain Bacteria and Archae include ONLY prokaryotic cells • Eukarya contain organisms with eukaryotic.

  17. Classifying living things • Bacteria- class smaller then Eukarya and have no nucleus • Archaea- Cells have a distinctive chemistry and can survive extreme environments. • Eukarya- larger and contain more complex structures

  18. Classifying living things • Six Kingdoms • After domains, all organisms fall into one of six kingdoms • Plantae (includes plants, trees, grass, and moss) • Animalia (animals from lions to bugs to Multicellular microbes) • Protista ( organisms that don’t fit easily into animals, plant, or fungi. Either unicellular or have a simple Multicellular structure)

  19. Classifying living things • Fungi (mushrooms, molds and yeasts) • Archaea ( organisms that are similar to bacteria but have a cell structure so different they must fit in own kingdom) • Bacteria (unicellular with no nucleus) • Changed around 1990 from 5 kingdoms. • Chemical differences between cells • Protista should be arranged into smaller kingdoms because of the many differences among its species.

  20. Classifying living things • Two most familiar kingdoms are plants and animals. • Plantae • 250,000 plant species known on Earth. • Tiny moss to giant kelp • All plants multicellular • All plants can make their own food via photosynthesis • Can not move from place to place • Can turn to face the sun or light • Grow upward

  21. Classifying living things • Animalia • Already a million species in the kingdom • More then 90 percent are insects • All animals get energy from other organisms • Most have some type of mouth and • A nervous system • Has no cell wall like plants

  22. Classifying living things • Other organisms in remaining 4 kingdoms • Protista • Has a wide variety of organism • Most unicellular • Have large complex cells with true nucleus (eukaryote) • Some eat other organisms • Some can photosynthesize • Do not have specialized cells like plants, animals, or fungi • Most live in fresh or salt water Euglena sp.

  23. Classifying living things • Some organisms, like seaweed are also classified as Protista • Fungi • Composed of molds, yeasts, mushrooms • Take in nutrients from their surrounding • Remain rooted in one place • Many fungi act as decomposers • Don’t photosynthesize

  24. Classifying living things • Archaea • Mid 1990’s changed classification of bacteria • Do not have a nuclei • But cell structure is different from that of bacteria • Live in water environments • Live in extreme environments like boiling mud near geysers, Hot vents, bottom of oceans, salt ponds, deep in sand

  25. Classifying living things • Bacteria • Live just about everywhere. • Most are helpful • Some harmful • All unicellular • Have small cells without a nucleus • Have a cell wall but not the same as plants

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