Lecture 13: Animal Classification تصنيف الحيوان

1. Lecture 13: Animal Classificationتصنيف الحيوان Systematic/Taxonomy علم التصنيف • Systematic includes taxonomy, which is the naming تسمية and classification تصنيفof species and groups of species. • Taxonomy: is that branch of biology dealing with the identificationتعريف and namingتسمية of organisms. • Aristotleأرسطو(ancient Greek philosopher) began the science of taxonomy. • Carolus Linneusكارلوس لينياس(1700s) (Swedish botanist) classified all then-known organisms into two large kingdoms: a) Kingdom Plantae المملكة النباتية b) Kingdom Animaliaالمملكة الحيوانية . • Robert Whittaker in 1969 proposed five kingdoms: Plantae, Animalia, Fungi, Protista, and Monera. • Recent studies suggest that three domains be employed: Archaea, Bacteria, and Eukarya

2. Animal Taxonomy • Linneus classified species النوعas the smallest unit, and that each species nested within يندرج تحتa higher category • Species is a Latin word meaning “kind” or “appearanceالشكل الظاهري ”. • Differentiation between species based on: a)- Morphological differencesاختلافات شكلية b)- The potential to interbreedالقدرة على التزاوج with each other in natureto produce fertile offspringجيل خصيب

3. Traditional Classification التصنيف التقليدي • Traditional Classificationالتصنيف التقليدي : depends on both common ancestryالنًّسب and the amount of differences among groups. • The traditional, dating to Linneaus view, is that birds have feathersريش , reptiles have scalesحراشيف , and mammals have hairشعر . • Linneus placed each of these groups in a separate class within the Phylum Chordataشعبة الحبليات .

4. Binomial nomenclature التسمية الثنائية(الاسم الثنائي للحيوان) • Linneus developed the concept of binomial nomenclature, whereby scientists could communicate clearly. • Under the binomial system, each species is assigned a two-part latinized nameاسم لاتيني من قسمين , (a binomial): • The first part, the genusالجنس , is the group to which a species belongs. • The second part, refers to the speciesالنوع within the genus. • The first letter of the genus is capitalized and both names are italicizedandlatinized. • For example, Linnaeus assigned to humans the scientific name Homosapiens, which means “wise man”.

5. Systematic position of human الوضع التقسيمي للإنسان • Kingdom: Animaliaالمملكة الحيوانية • Phylum: Chordataشعبة الحبليات • Class: Mammaliaطائفة الثدييات • Order: Primatesرتبة الرئيسيات • Family: Hominidaeعائلة البشر • Genus: Homo الجنس البشري • Species: sapiensالإنسان Scientific name: Homosapiens(The Wise Man الإنسان العاقل)

6. Eukaryota 3 1 2 Three Kingdoms of life There are three Kingdoms of life" 1)- Bacteria (Eubacteria), 2)- Archaea, 3)- Eukaryota (Fungi, Protesta, Plantae & Animalia) Viruses are not considered living organisms.

7. 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, theyboth are structurallyorganized at theprokaryotic level.

8. 1- Prokaryotes (bacteria & archaea) • Prokarytes exist in habitatsالبيئات 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 metabolismsللتكامل الأيضي. • These relationships called (symbiosisتبادل المنفعة) in three types: • Commensalismالمعايشة: one partner receives benefitsالمنفعة while the other is not harmed or helped by the relationship. • Parasitismالتطفل : one partner, the parasite, benefits at the expense of the host. • Mutualismتبادل المنفعة: both partners benefit from each other.

9. A)- Archaea • Archaea are extremophiles, “محب للظروف القاسية” of extreme environments and can be classified into: a)- Extreme halophilesمحب للملوحة: • live in such saline places as the Great Salt Lake and the Dead Sea. • Some species require an extremely saltyشديدة الملوحة environment to grow. b)- Extreme thermophilesمحب للحرارة live in hot environments. • The optimum temperatures for most thermophiles are 60 - 80°C.

10. B)- bacteria • Bacteria is considered as the most known prokarotes. • The major bacterial taxa (species) are now accorded kingdom status by most prokaryotic systematistsعلماء التصنيف . • Different types of diseases are caused by bacteria including cholera, many sexually transmissible diseasesالأمراض الجنسية المعدية , and certain types of food poisoningالتسمم الغذائي. • However, more bacteria are beneficialمفيدة. • Bacteria in our intestinesأمعائنا 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 relationshipsعلاقة تبادل منفعة .

12. Harmful prokaryotes (Pathogenesالمُمْرضات ) • Some pathogens produce disease by invading the tissues of the host. • More commonly, pathogens cause illness by producing poisons, called exotoxinsالسموم الخارجية and endotoxins السموم الداخلية. • Pathogenic prokaryotes cause about half of all human disease. • The actinomycete that causes tuberculosis is an example of this source of symptoms.

13. Beneficial prokaryotes (النافعة) • 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 productsالمنتجات التجارية . • The application of organisms to remove pollutants from air, water, and soil is bioremediationمُنَقٍّيات أحيائية