How are Living Things alike yet Different? Ch. 15.2 Classifying Life Essential Question: How are Living Things alike yet Different? Why Do Biologist Classify Organisms? What are the levels of Classification? How are the Taxonomic Keys Useful?

Vocabulary Ch. 15.2 Classification- The process of grouping things based on their similarities. Taxonomy-The scientific study of how living things are classified. Binomial Nomenclature- The classification system in which each organism is given a unique, two-part scientific name indicating its genus and species. Genus- A classification grouping that consists of a number of similar, closely related species. Species- A group of similar organisms that can mate with each other and produce offspring that can also mate and produce.

Ch. 15.2 One million kinds of organisms on Earth( and the number keeps growing) In order to keep track, scientists group organisms based on similarities= classify them. e. i. supermarket store Biologists use ___________ to _________ living things into groups so that the organisms are easier to study. The scientific study of how living things are classified is called taxonomy. Taxonomy also involves naming organisms.

The Naming System of Linnaeus pg. 592 What is the scientific name for humans? H______ S________ The system scientists use, developed by Swedish botanist Carolus Linnaeus, is called binomial nomenclature (B.N.). (observable features) B.N. = each organism has a unique two-part scientific name. e.i. Felis concolor= puma The first word is the genus, a classification grouping that contains similar, closely related organisms. (share same characteristics) e.i. Felis= sharp, retractable claws, hunt other animals The second word often describes where an organism lives or its appearance Species is a group of similar organisms that can mate with each other and produce offspring that can also mate and reproduce.

Aristotle and Classification Classifying Life pg. 593 Aristotle and Classification Aristotle, an ancient Greek scholar, developed a classification system for animals.

Binomial Nomenclature- Pg. 593 Binomial Nomenclature- First word is capitalize, not the second word Names used Latin words Classifying animals by names makes it easy for scientist to communicate about organisms= they all use the same names If not classified, there would be too much confusion!!

What Are the Levels of Classification pg. 594 The classification system has eight levels. A domain is the highest level of organization. kingdoms. phyla. classes. orders. families. genera species. The more classification levels two organisms share, the more characteristics they have in common and the more closely related they are.

Most biologists today use a classification system that has eight levels. A domain is the highest level of organization. Within a domain, there are kingdoms. Within kingdoms, there are phyla. Within phyla are classes. Within classes are orders. Within orders are families. Each family contains one or more genera. Finally, each genus contains one or more species. The more classification levels two organisms share, the more characteristics they have in common and the more closely related they are.

Levels of Classification Classifying Life Domain Eukarya Levels of Classification As you move down these levels of classification, the number of organisms decreases. The organisms that remain share more characteristics with one another and are more related. Kingdom Animalia Phylum Chordata Class Aves Order Strigiformes Family Strigidae Genus Bubo Species Bubo virginianus

How are Taxonomic keys Useful? pg. 596 Taxonomic keys are useful tools that help determine the identity of organisms. A taxonomic key consists of a series of paired statements that describe the various physical characteristics of different organisms. By choosing one statement in each pair and following its directive, the identity of an unfamiliar organism can eventually be determined.

Identifying Organisms Classifying Life Identifying Organisms The six paired statements in this taxonomic key describe physical characteristics of different organisms.