Classifying Living Things Chapter 7 Life Science Mrs. Nell

Classifying To classify means to group ideas, information or objects based on similarities. We classify many places- like grocery stores, bookstores, and department stores.

Early Classification Systems Aristotle, a Greek philosopher, developed a system to classify living things. The science of classifying and naming organisms is called taxonomy. Aristotle’s classification system had two kingdoms- plant and animal.

Aristotle’s Classification System Aristotle divided the animal kingdom into organisms based on whether they lived in the air, on land, or in the sea. Amphibians, and other organisms, didn’t fit nicely into this system. He classified plants based on their size and structure.

Carolus Linnaeus Carl Von Linne, better known as Carolus Linnaeus, was a Swedish physician and naturalist that created a system to classify organisms based on their body structures and systems, size, shape, color, and method of obtaining food.

Binomial Nomenclature Linnaeus created a two-word naming system called binomial nomenclature. This system gave all organisms a scientific name in Latin. The first part of the scientific name was the genus and the second the species. Canis rufus Felis lynx

Species Organisms belonging to the same species can mate with one another to produce fertile offspring. Organisms like lions and tigers that are different species can have offspring together, but the offspring are sterile.

Modern Classification Today scientists look at the chemical makeup, similarities in genes and body structures, fossils, and embryos to determine an organisms phylogeny, or evolutionary history.

Similar DNA

Six Kingdoms Now we classify organisms into six kingdoms: Animal, Plant, Fungi, Protista, Eubacteria, and Archaebacteria.

Kingdom Monera (Bacteria) Kingdom Archaebacteria and Eubacteria are one-celled organisms. They are both prokaryotes (they don’t have an organized nucleus or membrane- bound organelles). Some members can make their own food, but others obtain food from other organisms. Archaebacteria live in extreme environments!

Kingdom Protista Protista are eukaryotic (they have an organized nucleus and organelles). They can be one celled or many celled. Some move- some don’t. Some make their own food, some must obtain food from other organisms. Some are similar to plants, some to animals, and some to fungi. Amoeba Euglena Slime mold

Kingdom Fungi Fungi are eukaryotic. They are single or many celled. They do not move. They obtain food from other organisms. Yeast Mushroom Morel Mold

Plant Kingdom Plants are eukaryotic. They are many celled and don’t move. They can make their own food. Moss Fer n Flowers Trees

Animal Kingdom Animals are eukaryotic. They are many celled and can move. They eat plants and other animals for food.

Pyramid The organization of living things can be seen like a pyramid or tree with seven major levels or categories: Kingdom, Phylum (or Division), Class, Order, Family, Genus, Species. The phrases “Kings Play Cards Over Family Games Sometimes” or “Kids Pick Candy Over Fancy Green Salads” help us remember these taxonomic groups.

Diminishing Diversity There is a great variety of plants, animals, and other organisms on our planet. An ecosystem with a high species diversity is more stable than one with fewer species. Some people feel that, while species diversity is important, that the livelihoods of people are more important. Others feel that species diversity is more important than human needs to use resources.

Northern Spotted Owl The endangered northern spotted owl was the focus of a recent controversy between loggers and activists in the northwestern United States.

Common Names There are many common names for the same organism. Using common names can result in errors in understanding. Scientific names: 1) help scientists avoid errors in communication. 2) Group organisms with similar evolutionary history together. 3) Give descriptive information about the species. 4) Allows information about the organism to be organized and found easily. Common Names: Puma, Mountain Lion, Mountain Cat, Panther Scientific Name: Puma concolor

Dichotomous Keys Scientists classify organisms by using detailed lists of traits called dichotomous keys. Field guides use descriptions like physical characteristics and information about where they can be found to help in identification of an organism.