Classification of Organisms Chapter 15 Pre-AP Biology, Dr. Shufran 2015

Why Classify Organisms? 1.6 million species identified thus far (p. 319 of your text; incorrect figure) – 950,000 insects – 350,000 plants – 5,416 mammals Possibly >8 million species on the planet Help understand the diversity of life and make the information manageable

What is taxonomy? The branch of science naming organisms and assigning them to groups. Group = taxon (Plural = taxa) Carolus Linnaeus: The Father of Taxonomy

Hierarchy of Classification Organisms are Placed in Taxa Kingdom Phylum Class Order Family Genus Species Lowest number (6) Highest number (1.6 million)

Animalia Arthropoda Insecta Hymenoptera Apidae Apis A. mellifera

Animalia Chordata Mammalia Carnivora Canidae Canis Canis lupus

The Six Kingdoms

autotroph [ ("self-feeding", from the Greek autos "self" and trophe "nourishing"). Plants fix carbon and produce their own food. heterotroph (heteros = "another", "different" and trophe = "nutrition") Animals, fungi, and bacteria cannot fix carbon and must obtain it from food.

Prokaryote: Greek (pro-) "before" and (karyon) "nut or kernel" Lack a membrane bound nucleus, mitochondria and other membrane bound organelles Bacteria: Escherichia coli Staphylococcus aureu MRSA: Methicillin-resistant S. aureu

Eukaryote; Greek (eu, "well") and (karyon, "nut" or "kernel"). Have membrane-bound organelles, especially the nucleus All multicellular organisms are eukaryotes, including animals, plants and fungi.

Order Sub-Order Family Genus Cat-Like Dog-Like A phylogeny of Carnivora

Macaque (Rhesus) Chimpanzee (Pan)

DNA sequencing: alignment of DNA sequences Humans and Chimpanzees share 95-98% Same DNA-Goodall