Chapter 2.1 (pages 46-51)

Key concepts: Explain why and how organisms are classified. List the eight levels of classification. Explain scientific names. Describe how dichotomous keys help in identifying organisms.

Key Vocabulary: Element Compound Pure substance Properties Ratio

In a world of games: We take a look in a yearbook. What do we see?

Classification: Classification is putting things into orderly groups based on similar characteristics. How do biologists classify things on our planet? – What are the defining characteristics of each species? – When did the characteristics of a species change? – What are the relationships between different species? Where have we discussed classification before? When do you classify things in your life?

Timeline of classification: Before 1600’s: – Plants and animals – Why didn’t this work? 1700’s-Linnaeus: Swedish scientist whose system was based on the structure or characteristics of organisms. – Founded modern taxonomy (taks AH nuh mee). – Taxonomy is the science of describing, classifying, and naming organisms.

Taxonomy: Taxonomists use an eight-level system to classify living things based on: – shared characteristics. These are used to also describe how closely related living things are. Biggest to smallest: D, K, P, C, O, F, G, S Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species What are properties?

Taxonomy: Scientists use shared characteristics to group organisms into eight levels of classification. – There are fewer organisms than in the level above (becomes more specific) – A domain is the largest, most general level of classification. one of three domains. – Species is the smallest level of classification. A species is a group of organisms that can mate and produce fertile offspring. For example, dogs are all one species. Three domains: - eukaryote -prokaryote -Archeabacteria Only 1 species for every type of organism (most specific)

Taxonomy: Naming: – Common names: Cat, dog, and human cougar, mountain lion, and puma are three names for the same animal – Scientific names: Scientific names are the same in all languages. An organism has only one scientific name. Why is this important? – Scientific names are based on the system created by Linnaeus. He gave each kind of organism a two-part name. the first part of the name is the genus, and the second part is the species. Asian elephant is Elephas maximus. Homo sapiens Both words in a scientific name are underlined or italicized All genus names begin with a capital letter. All species names begin with a lowercase letter.

Binomial Nomenclature: Two part name “Bi” – “nomial” Two part name “Bi” – “nomial” Genus Felix

Review: What are compounds? What is a chemical reaction? How are compounds used in everyday life? A compound has 39 g of potassium and 78 g of selenium. What is the mass ratio of potassium to selenium in the compound?

Homework: Vocabulary cards for the following term: – Compound Questions on page 241: Write the ? – Do this on the back of your notes: – # 3, 4 and 5 Vocabulary cards for the following term: – Compound Questions on page 241: Write the ? – Do this on the back of your notes: – # 3, 4 and 5