CLASSIFICATION CHAPTER 3

DISCUSSION Why do we have two names? Choose a first name that you hear often. Make a list of all the people you know who have the same first name. Can you see why a two-name system is needed? THINK ABOUT YOUR CLOSET – HOW IS IT ARRANGED?

WHY DO WE CLASSIFY? Classify – group things together based on similarities * Why: easier to find show how they share certain traits (trait is a feature that a thing has) Organisms are classified by their: *physical structure (how the look) *evolutionary relationships *embryonic similarities (embryos) *genetic similarities (DNA) *biochemical similarities Biologist have a system for grouping living things. Each living thing has a specific name that biologists all over the world understand.

DO NOW!!!! What is meant by a trait? Give two examples of traits. Give an example of something at school that is classified. Give two reasons why things are classified.

EARLY CLASSIFICATION Aristotle – Greek scientist was one of the first people to classify living things. Living things fit into two main groups: Plant and Animal He next divided them into three groups based on where the animals live * Water * Land * Air (fly) Grouping Plants based on size and pattern of growth. He based this on Tall, Medium and Small.

Modern Classification Scientists found more and more living things. Many did not fit into Aristotle’s system. Can anyone give us an example? In 1735 Carolus Linnaeus developed a new classification system. He placed living things into two main categories – he called them KINGDOMS PLANTS ANIMALS Kingdom – is the largest group of living things He placed living things with similar traits into the same group and called this group a species. Linnaeus made a number of important changes: 1. He classified plants and animals into more groups 2. He based his system on specific traits 3. He gave organisms names that described their traits. These names had two parts. All living things still have two part names.

Classification System Today there are seven groups for classifying organisms. Kingdom Phylum – the largest group within a kingdom Class – the largest group within a phylum Orders – the largest group within a class Family – the largest group within an order Genus – the largest group within a family Species – the smallest group of living things MNEMONIC DEVICE: King Phillip came over for good strawberries.

Comparing classification groups and address information Kingdom Largest country Phylum state Class counties Order town Family neighborhood Genus street Species Smallest house number

Group Group Name Group Trait Scientists look at traits to determine which groups an organism belongs to. Living things that are closely related are in many of the same classification groups. Group Group Name Group Trait Kingdom Animal Has many cells;eats food Phylum Chordate Rodlike structure along the back for support Class Mammal Nurses young; has hair Order Carnivore Eats flesh; has large teeth Family Felidae Sharp claws; large eyes Genus Felis Small cats Species Catus Tame

CLASSIFICATION: Can be based on a living thing’s ancestors similar body structures often show that living things have common ancestors Another way to group living things is by body chemistry

Scientific Names Come from Classification Scientific name – the genus and species names together make this up Living things are classified down to genus and species Cat Felis catus Genus is ALWAYS capitalized Wolf Canis lupus

Why are Scientific Names Used? No mistake can be made about which a living thing is described Scientific names seldom change Scientific names are written in the same language around the world Latin is used because it does not change

Five Kingdom Classification Early scientists grouped living things into two kingdoms – plant and animal A new system of classification was needed to group all the living things being discovered. Today most scientists use this system to classify living things into five kingdoms.

FIVE KINGDOMS Monerans – one celled organism with no nucleus lack most cell parts Protists – single celled organisms that have a nucleus and other cell parts Fungi – have cell walls and absorb food from their surroundings. CANNOT MAKE THEIR OWN FOOD Plants – made up of many cells, have chlorophyll and CAN make up their own food, CAN’T MOVE Animals – organisms that have many cells, CAN’T MAKE their own food and CAN move Mnemonic Device:

seven groups – kingdom, phylum, class, order, family genus, species evidence – same ancestors, similar body structure, body chemistry Modern organisms given two part scientific name Classification Kingdoms – moneran, protist, fungus, plant, animal

DO NOW!!!! How is similarity in body structure used to classify living things? Give two reasons why scientists use scientific names. What are five kingdoms recognized today in classification?

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