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. Each year, about 13,000 new species are added to the list of known organisms. So, how do scientists classify (organize) all these millions of species?

2 Types of Cells 3 Domains and 4 Kingdoms EUKARYOTES PROKARYOTES organisms with a nuclear membrane PROKARYOTES organisms with no nuclear membrane

Life's History and Diversity The Big Picture 9/15/2018 Biol 1010, G. Podgorski

Life's History and Diversity 9/15/2018 The History of Life on Earth Multicellular eukaryotes (with nuclear 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. Biol 1010, G. Podgorski

Nucleolus Nuclear membrane List the similarities and differences between Eukaryotes and Prokaryotes.

Life's History and Diversity Archaea 9/15/2018 The Archaea are one of two groups of prokaryotic 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 Archaea do not require sunlight for photosynthesis, as plants do, and they do not need oxygen. Archaea absorb CO2, N2, or H2S and give off methane gas as a waste product. Archaea are best known for living in extremely hostile environments (very hot, very acid, or very salty), but they can also be found in less extreme conditions. Biol 1010, G. Podgorski

Life's History and Diversity 9/15/2018 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. Biol 1010, G. Podgorski

Life's History and Diversity 9/15/2018 What Good Are Bacteria? Bacteria are the primary recyclers of materials in the environment, particularly nitrogen. Newsflash!!! Bacteria discovered that can do photosynthesis! Biol 1010, G. Podgorski

Life's History and Diversity 9/15/2018 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. Biol 1010, G. Podgorski

The Domain Eukarya is divided into 4 Kingdoms: Protista Fungi Plantae Animalia Classifying Critters activity

PROTISTS • Protists are eukaryotes because they all have a nucleus. • Most have mitochondria. • Many have chloroplasts with 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 Fungi sometimes look like plants, but they’re not! Fungi can’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 fungi feed 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 as symbiotic 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)

Animal Classification

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 Order Family Genus Species Class Remember: Kids Prefer Candy Over Fresh Green Salad

Subfamily: Panthernae Genus: Panthera Species: Tigris Kingdom:  Animalia Phylum:   Chordata Class:     Mammalia Order:    Carnivora Suborder:   Aeluroidae Family:   Felidae Subfamily:   Panthernae Genus:  Panthera Species:               Tigris                     Subspecies               Panthera tigris altaica Siberian or Amur Tiger, Southeast Russia/China  Panthera tigris tigris India   Panthera tigris amoyensis Southern China   Panthera tigris corbetti Indochina Panthera tigris sumatrae Sumatran Tiger, Sumatra                 

Life's History and Diversity 9/15/2018 Primates – Our Order within the Class Mammalia Humans: Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: H. Sapiens Biol 1010, G. Podgorski