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CLASSIFICATION. We classify in order to organize. We classify to recognize relationships among organisms. We classify to study the evolutionary history of organisms (phylogeny). Why Do We Classify?. Aristotle was a Greek philosopher and scholar.
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We classify in order to organize. We classify to recognize relationships among organisms. We classify to study the evolutionary history of organisms (phylogeny). Why Do We Classify?
Aristotle was a Greek philosopher and scholar. Divided organisms into 2 groups - plants and animals. Divided animals into blood and bloodless. Divided animals into groups based on number of legs. Divided animals into 3 groups according to how they moved - walking, flying, or swimming (land, air, or water) History of Classification
Carolus Linnaeus was a Swedish scientist. Classified plants and animals according to similarities in form. Divided living things into one of two "kingdoms" – Plant or Animal Divided each of the kingdoms into smaller groups called "genera" (plural of "genus"). Divided each genera into smaller groups called "species“. History of Classification
The Evolution of Our Classification System • The Linnaean System is used by scientists all over the world, but has been expanded to include new and different living things as they are discovered. It will continue to grow as human knowledge grows.
CLASSIFICATION – TAXONOMY – ORGANISM – BINOMIAL NOMENCLATURE – EVOLUTION – Grouping things based on their similarities. The science of classifying organisms. Any living thing. A two-part scientific name (Genusspecies). Species change gradually over time. Classification Terminology
The classification system in use today places each living thing into a series of specific groups based on similarities and differences in body structure, color, behavior, etc. Our Current Classification System
The largest group into which any living thing can be classified is its kingdom. This is followed by its phylum or division, then its class, order, family, genus, and finally its species. Our Current Classification System
Most biologists use a classification system based on five kingdoms. The Kingdoms
The number of kingdoms is often under debate, depending on how scientists interpret current research. For example, some scientists separate the Moneran into two kingdoms. The Kingdom Debate
Taxonomists divide organisms into a series of groups (divisions) that get more and more specific. The most general division of life is a kingdom. The most specific division of life is a species. Our Hierarchical System
Within each kingdom, there are groups, increasing in commonality and evolutionary relationships, but decreasing in size (fewer numbers). For example, two organisms in the same order have more in common than two organisms in the same class. Our Hierarchical System
Moneran Kingdom • Bacteria are among the oldest living organisms on Earth, and are very small. • Because the bacteria structure is so minute, it can only be seen through a microscope. • Bacteria are unicellular prokaryotes. • Bacteria is commonly found in the ground, water and in other living organisms. • Most bacteria are heterotrophs but some bacteria like blue-green algae are autotrophs.
While some types of bacteria can cause diseases and become harmful to the environment, animals and humans, others offer benefits that we likely could not live without. Moneran Kingdom
Some types of bacteria can attack plants, causing diseases like leaf spot and fire blight. Harmful Bacteria
In human hosts, certain types of bacteria can cause tetanus, pneumonia, syphilis, tuberculosis and other illnesses. Humans can be treated with antibiotics, which kill bacteria or at least hamper their growth. Antiseptics, sterilization and disinfectants can help prevent contamination and risk of infection from bacteria. Harmful Bacteria
The term “friendly bacteria” is used to describe the types of bacteria that offer some benefit. Not only does bacteria help produce the food we eat and keeps the soil fertile, it also helps us digest our food. Bacteria in our digestive system help to convert milk protein into lactic acid and inhibit the growth of potentially harmful bacteria. Helpful Bacteria
Archaebacteria “ancient bacteria” Found in very harsh conditions such as in the volcanic vents or at the bottom of the sea. They survive in the environments such as sea vents releasing sulfide-rich gases, hot springs or boiling mud around volcanoes. “extremophiles” All forms of archaebacteria are non-pathogenic. Eubacteria “true bacteria” Cyanobacteria – blue-green algae Most bacteria are in this kingdom. They are the kinds found everywhere and the ones people are most familiar with. Archaebacteria vs. Eubacteria
This is sometimes called the “odds and ends” kingdom. A protist is any organism that is not a plant, animal or fungus. Mostly unicellular, some are multicellular (algae) Can be heterotrophic or autotrophic. Most live in water (though some live in moist soil or even the human body). ALL are eukaryotic (have a nucleus). Protozoan Kingdom
How they obtain nutrition How they move Animal-like Protists - protozoa - heterotrophs Plantlike Protists - algae autotrophs Fungus-like Protists – heterotrophs & decomposers Classification of Protists
Mushrooms Molds Yeasts Mildews Fungi Kingdom
Most fungi are multicellular (yeast is unicellular). All fungi are eukaryotic heterotrophs. Fungi can be found almost everywhere on land, but only a few live in fresh water. Fungi Kingdom
Fungi are some of the most important organisms in terms of their ecological and economic roles. By breaking down dead organic material, they continue the cycle of nutrients through ecosystems. Most vascular plants could not grow without the fungi that inhabit their roots and supply essential nutrients. Other fungi provide numerous drugs (such as penicillin and other antibiotics), foods like mushrooms, truffles and morels, and the bubbles in bread, champagne, and beer. A number of fungi, in particular the yeasts, are important "model organisms" for studying problems in genetics and molecular biology. The Importance of Fungi
Fungi also cause a number of plant and animal diseases. In humans, ringworm, athlete's foot, and several more serious diseases are caused by fungi. Plant diseases caused by fungi include rusts, smuts, and leaf, root, and stem rots, and may cause severe damage to crops. Bad Fungi?
Plants are multicellular eukaryotes. Plants are autotrophs and make their own food through the process of photosynthesis. Plants feed almost all of the heterotrophs on Earth. Plant Kingdom
All animals are multicellular eukaryotes. All animals are heterotrophs. Animals have adaptations that allow them to find food and digest it. Members of the animal kingdom are found in diverse environments on earth. Animal Kingdom
