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Classification of Living Things. Scientists estimate that there are between 3 million and 100 million species of organisms on Earth. Taxonomists --biologists who specialize in identifying and classifying life on our planet--have named approximately 1.7 million species so far.
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Classification of Living Things Scientists estimate that there are between3 millionand100 millionspecies of organisms on Earth. Taxonomists--biologists who specialize in identifying and classifying life on our planet--have named approximately1.7 millionspecies so far. Each year, about13,000new speciesare added to the list of known organisms. So, how do scientists classify (organize) all these millions of species?
2 Types of Cells 3Domains and 4 Kingdoms EUKARYOTES organismswitha nuclear membrane PROKARYOTES organisms withnonuclear membrane
The Big Picture
The History of Life on Earth Multicellulareukaryotes(withnuclear membrane) evolved about 1 billion years ago. For 2.6 billion years, life was unicellular. Life began on Earth 3.6 billion years ago as a prokaryotic cell (single-celled organism with no nuclear membrane). The Earth formed 4.5 billion years ago.
Nucleolus Nuclear membrane List thesimilaritiesand differencesbetweenEukaryotesand Prokaryotes.
Life’s History and Diversity Line length reflects evolutionary distance. Note the close spacing of the groups plants(maize),fungi(yeast)and animals(humans). We’ve got a lot more in common with bacteria and plants than we think!
Life’s History Animals diversified in the ocean about600 million years ago. in the ocean Plants colonized land about440 million years agoand were followed shortly by animals. Humans of any sort are a very recent evolutionary development (~7 million years ago).
Archaea TheArchaeaare one of two groups ofprokaryotic organisms, organisms with no nuclear membrane. (Bacteria are the other group.) Archaea are believed to be the earliest form of life on Earth. Although both archaea and bacteria are simple life-forms, archaea are very different from bacteria. ARCHAEA Archaeado not require sunlightfor photosynthesis, as plants do, and theydo not need oxygen.Archaeaabsorb CO2, N2, or H2S and give off methane gas as a waste product. Archaea are best known forliving in extremely hostile environments(very hot, very acid, or very salty), but they can also be found in less extreme conditions.
A Deep Sea Hydrothermal Vent – Prime Habitat forArchaean Extremophiles video of black smoker
Hot springs in Yellowstone Park–“Hot” Spots forArchaean Extremophiles Prismatic Pool, Yellowstone Park Searching for Archaea in Yellowstone’s Obsidian Pool Archaeain Yellowstone
Bacteria– the Most Abundant Organisms Bacteria (Staphylococcus aureus; yellow spheres) adhering to nasal cilia. Mycoplasma hyopneumoniae Borrelia burgdorferi, the bacterium that causes Lyme disease. E. Coli bacteria There are more bacteria in your mouth than there have been people living since the dawn of humans.
What Good Are Bacteria? Bacteria are theprimary recyclers of materials in the environment, particularly nitrogen. Newsflash!!! Bacteria discovered that can dophotosynthesis!
What Good Are Bacteria? Bacteria are also essential for many processes we depend on – sewage treatment, cheese production, antibiotic production, and biotechnological processes like gene cloning and protein production.
Bacteria are used to produce insulin and other drugs that people need.
The Domain Eukarya is divided into 4 Kingdoms: Protista Fungi Plantae Animalia Classifying Critters activity
PROTISTS • Protistsare eukaryotesbecause they all have a nucleus. • Most have mitochondria. • Many have chloroplastswith which they carry on photosynthesis. • Many are unicellular and all groups (with one exception) contain some unicellular members. A better name for Protists would be "Eukaryotes that are neither Animals, Fungi, nor Plants". Protists Visit Protist Park
FUNGI Fungi sometimes look like plants, but they’re not! Fungican’t do photosynthesis, because they don’t have chloroplasts; they get their nutrients from the organic material they live in. Decomposers, like mushrooms, feed on dead organic material. Some fungifeed on living organisms, such as plants, animals and even other fungi. This causes diseases and infections in these organisms (like athlete’s foot and ringworm in humans). Some fungi live assymbiotic partners with algae. The result:lichen(pronounced “like-n”). more lichen Other differences from plants: • fungi don’t have roots, they have a mycelium. FUNGI • fungi’s cell walls are made of chitin, not cellulose.
PLANTS No vascular system Vascular system Mosses, Liverworts, Hornworts Seedless Plants (reproduce by spores) Seed Plants (reproduce by seeds) Ferns, Horsetails, Club Mosses Gymnosperms(“naked seeds”) Angiosperms(flowers, seeds enclosed in fruit) Conifers Cycads Gingkoes Flowering Plants
ANIMALS Invertebrates (no backbone) Vertebrates(backbone)
As you can see, we mammals (4000 species) are far outnumbered by the other vertebrates, or chordates (38,300). And vertebrates (42,300) are definitely outnumbered by invertebrates (989,700 species). The biggest categories of invertebrates: INSECTS!
3 members of the genus “Felis” (cat). Taxonomy, or classification, enables scientists to assign a very specific name to every species, so that scientists all over the world know exactly what species is being referred to.
Kingdom Phylum Class Class Order Family Genus Species Remember:Kids Prefer Candy Over Fresh Green Salad
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Suborder: Aeluroidae Family: Felidae Subfamily: Panthernae Genus: Panthera Species: Tigris Subspecies PantheratigrisaltaicaSiberian or Amur Tiger, Southeast Russia/China PantheratigristigrisIndia PantheratigrisamoyensisSouthern China Pantheratigriscorbetti Indochina PantheratigrissumatraeSumatran Tiger, Sumatra
Primates– Our Order within the Class Mammalia Humans: Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: H. Sapiens
This is approximately where the last 60 million years of primate evolution has occurred.
Dichotomous Key • Tool used by biologists to identify an unknown organism • Series of paired statements of anatomical description that leads to an identification. S5
Bird W is Geospiza • Bird X is Platyspiza • Bird Y is Certhidea • Bird Z is Camarhynchus
Key for Vertebrate Identification • 1. a) animal has a spine…………………..go to 2 b) animal has no spine………..…invertebrate 2. a) animal has no gills and fins……..…. go to 3 b) animal has gills and fins…………….. Fish 3. a) animal has no scales…………..........go to 4 b) animal has scales………………..….reptile 4. a) animal has feathers …………………..bird b) animal has no feathers ……………..go to 5 5. a) animal has hair…………………….mammal b) animal has no hair………………..amphibian What am I ???