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Animal Taxonomy Kingdoms of life Three Kingdoms of life 2 1 3 prokaryotic 3 There are three Kingdoms of life" 1 Bacteria (Eubacteria), 2 Archaea, 3 Eukaryota Eukaryota (Fungi, Protesta, Plantae & Animalia) 1 2 1- Prokaryotes (bacteria & archaea) • Current taxonomy recognizes two prokaryotic domains (Kingdoms): domain Bacteria and domain Archaea. • Bacteria and archaea exist so early in life and are very different. • At the same time, they both are structurally organized at the prokaryotic level. 1- Prokaryotes (bacteria & archaea) • Prokarytes exist in habitats that are too cold, too hot, too salty, too acidic, or too alkaline for any eukaryote. Prokaryotes often interact with other species of prokaryotes or eukaryotes with complementary metabolisms. • • These relationships called (symbiosis) in three types: 1. Commensalism : one partner receives benefits while the other is 2. 3. not harmed or helped by the relationship. Parasitism : one partner, the parasite, benefits at the expense of the host. Mutualism: both partners benefit from each other. A)- Archaea • Archaea are extremophilesof extreme environments and can be classified into: a)- Extreme halophiles: • live in such saline places as the Great Salt Lake and the Dead Sea. • Some species require an extremely salty environment to grow. b)- Extreme thermophiles live in hot environments. • The optimum temperatures for most thermophiles are 60 - 80°C. B)- bacteria • Bacteria is considered as the most known prokarotes. • The major bacterial taxa (species) are now accorded kingdom status by most prokaryotic systematists. • Different types of diseases are caused by bacteria including cholera, many sexually transmissible diseases, and certain types of food poisoning. • However, more bacteria are beneficial . – Bacteria in our intestines produce important vitamins. – Bacteria recycle CO2 and other chemical elements between organic matter and the soil and atmosphere. • Bacteria often live in close association among themselves and with eukaryotes in symbiotic relationships. Most common shape of bacteria 1- cocci :are spherical shape 2- Bacilli: are rode shape 3- spiral : range from comma –like shape to long coil • Spherical, rod shape or spiral occur singly or in pair Harmful prokaryotes (Pathogenes) • Some pathogens produce disease by invading the tissues of the host. • More commonly, pathogens cause illness by producing poisons, called exotoxins and endotoxins. • Pathogenic prokaryotes cause about half of all human disease. • The actinomycete that causes tuberculosis is an example of this source of symptoms. Beneficial prokaryotes • Humans have learned to exploit the diverse metabolic capabilities of prokaryotes, for scientific research and for practical purposes. • Prokaryotes are used to solve environmental problems. • Humans also use bacteria as metabolic “factories” for commercial products. • The application of organisms to remove pollutants from air, water, and soil is bioremediation Viruses • Virus :is a small infectious agent that can replicate only inside the living cells of organisms • Consist of two part : 1- the genetic material made from either DNA or RNA, long molecules that carry genetic information. 2- a protein coat that protects these genes; and in some cases an envelope of lipids that surrounds the protein coat when they are outside a cell. • Virus reproduce only in the host cell and cause disease by damage and kill the cell by producing toxin The Summary ? Viruses Fungi Plants Three Kingdom of life Eukaryotes Archae bacteria Animals Protista Eubacteria