Classification

1. Taxonomy: hierarchy Domains: prokaryotes vs. eukaryotes Classification

2. Why do we classify? �Because there are so many known species, a system of classification is needed for 3 reasons: ������������a.���������Organize species into groups and discuss them. ������������b.���������Identify new organisms. ������������c.���������Show relationships between organisms.

3. Evidence for evolution Why? Biochemical Anatomy embryology -those with similar DNA are more closely related -those with similar physical properties are more related Those that looked similar at birth more related. How do we classify

4. Recall: Anatomy Similar structure means common ancestor The more homologies two organisms possess, the more likely it is that they have a close genetic relationship In the earlier days, scientists like Carolus Linnaeus based classification on physical features Homologies (structures)

5. Write your description based on 5 physical characteristics. Class activity

6. How many species are there Who came up with a system? 13-14 million species Majority are microscopic probably haven't even seen before 1.8 millions have scientific names Carlus Linnaeus Came up with a system for describing and naming species Invented a system of classification Classification

7. Carlous Linneau Developed a system of hierarchy A system of ranking and organizing species There are 8 ranks ( taxons) to the hearty Taxon: group of organisms with an evolutionary relationship Domains, kingdom, phylum, class, order, family, genus, species Mnemonic: dignified kings play chess on fine green silk Make your own

8. Domains Kingdom Based on cell type Eukaryotic Vs prokaryotic Based on cellular organization Single vs. multi cellular Mode of nutrition Make own food or get food from other sources: how does it obtain food Ex: absorb, ingest Taxonomic heirchay

9. Phylum Class based on basic body plan: internal organization -Hard bodied vs. soft bodied Based on: Skeletal system, general environment adaptation and reproductive system How they reproduce and care for young Taxonomy heirchy

10. SPECIES: ORDER FAMILY GENUS SPECIES INCREASED SIMILARITY Can reproduce to produce fertile offspring

11. Example: Uses the genus and species name: Ex: humans the scientific name for humans is Homo sapiens. (Genus Homo=man, specific epithet sapiens=thinking. Literally, in Latin, thinking man Domain: Eukaryota (organisms which have cells with a nucleus) Kingdom: Animalia (with eukaryotic cells having cell membrane but lacking cell wall, multicellular, heterotrophic) Phylum: Chordata (animals with a notochord, dorsal nerve cord, and pharyngeal gill slits, which may be vestigial) Subphylum: Vertebrata (possessing a backbone, which may be cartilaginous, to protect the dorsal nerve cord) Class: Mammalia (endothermic vertebrates with hair and mammary glands which, in females, secrete milk to nourish young) Cohort: Placentalia (giving birth to live young after a full internal gestation period) Order: Primates (collar bone, eyes face forward, grasping hands with fingers, and two types of teeth: incisors and molars) Family: Hominidae (upright posture, large brain, stereoscopic vision, flat face, hands and feet have different specializations) Genus: Homo (s-curved spine, "man") Species: Homo sapiens (high forehead, well-developed chin, skull bones thin) Binomial classification

12. Humans Domain: Eukaryota (organisms which have cells with a nucleus) Kingdom: Animalia (with eukaryotic cells having cell membrane but lacking cell wall, multicellular, heterotrophic) Phylum: Chordata (animals with a notochord, dorsal nerve cord, and pharyngeal gill slits, which may be vestigial) Class: Mammalia (endothermic vertebrates with hair and mammary glands which, in females, secrete milk to nourish young) Order: Primates (collar bone, eyes face forward, grasping hands with fingers, and two types of teeth: incisors and molars) Family: Hominidae (upright posture, large brain, stereoscopic vision, flat face, hands and feet have different specializations) Genus: Homo (s-curved spine, "man") Species: Homo sapiens (high forehead, well-developed chin, skull bones thin)

13. 3 domains of life 3: Archea: extreme bacteria Prokaryotic cells Prokarya or bacteria Prokaryotic cells Eukaryota: Eukaryotic cells Domains:

14. Archea Bacteria Microorganism that live in extreme environments Primitive e forms of bacteria hot springs More advanced forms of bacteria Prokaryotic cells

15. Prokaryotic Cells ��(1)�������Prokaryotic cells are smaller and more primitive. �(2)�������They have few organelles and their organelles have no membranes. The cell has no nucleus. Many prokaryotes have a rigid cell wall. They are able to grow and multiply quickly because of their small surface area: volume ratio. ��(3)�������They are bacteria and cyanobacteria (blue-green algae).

16. Eukaryotic Cells 1) are more advanced, larger, and contain organelles. These cells have a nucleus. All species other than bacteria and cyanobacteria are eukaryotes. This includes protists, fungi, plants, and animals, as well as humans. 2) Organelles allow many activities to take place within the same cell

17. Prokaryotes Eukaryotes No Nucleus---Genetic Information Floats around in Cytoplasm No Membrane-Bound Organelles Much Smaller in size Very Simple Structure Have a Nucleus that contains Genetic Information Have Membrane-Bound Organelles Generally Larger in size Very Complex Structure comparison