Chapter 3.2 – Classifying and Naming Organisms (pages 85 – 92) Chapter 3.2 – Classifying and Naming Organisms

3.2 Classifying and Naming Organisms In this section you will: Explain how organisms are classified in domains and kingdoms Explain how organisms are names using a two-name system called binomial nomenclature Identify species using a dichotomous key

The Classification of Organisms Taxonomy: the practice of classifying living things

Classification Because of the differences in languages and cultures ecologists needed a common method of classifying organisms to improve scientific communication. Taxonomy- Practice of classifying living things https://www.youtube.com/watch?v=t3amU3RrX9g

Early Classification Aristotle (Greek philosopher) began classifying organisms into kingdoms (plants and animals) Kingdom Plantae Kingdom Animalia There was further classification based on size, movement, etc. BUT there were limitations to such classification The discovery of micro-organisms forced scientists to reconsider criteria. Ernst Heckel Neither animal nor plant- Protista Taxonomy began approximately 2000 years ago when Aristotle divided the 1000 known organisms into two large groups: plants and animals. He called each group a kingdom. Aristotle further classified animals based on their size and the way they moved. Aristotle classified plants based on their stem characteristics. Aristotle’s method of classification had limitations and was changed over time.

Life is currently divided into 6 distinct kingdoms and 3 domains: 3 Domains of Life 6 Kingdoms of Life Archaea Bacteria Eukaryota Archaea Bacteria Protista Fungi Plantae Animalia

Domains The six-kingdom system recently revised Three major domains, which are large groups that encompass all the kingdoms Eukarya Bacteria Archaea https://www.youtube.com/watch?v=vAR47-g6tlA NOT IN NOTES

The Six Kingdoms Archaea Bacteria Protista Fungi Plantae Animalia Single-celled prokaryotic organisms that live in extreme environments Bacteria Single-celled prokaryotic organisms that live in a wide range of habitats Protista Consists of both single and multi-celled eukaryotic organisms Fungi Single and multi-celled eukaryotes that secrete enzymes to digest their food Plantae Eukaryotic multi-celled organisms that use photosynthesis Animalia Eukaryotic multi-celled organisms that are heterotrophs With a partner: Come up with a way to remember these Kingdoms! Can copy the features of kingdom.

Multiples chromosomes True membrane bound nucleus HOLD UP: Do you remember this? Eukaryotes Prokaryotes Animals and Plants Multiples chromosomes True membrane bound nucleus Nucleus- powerhouse/brain Bacteria and Archaea One, but not true chromosome (plasmids) No membrane bound nucleus HOLD UP: Do you remember this?

Archaea single-celled lack membrane bound nucleus capable of living in extreme environments Examples: deep sea vent bacteria, thermal springs bacteria

Bacteria single-celled lack membrane bound nucleus Examples: E. coli, salmonella

Protista cells contain a nucleus (eukaryotic) Unicellular and multicellular autotrophs and heterotrophs Examples: algae and protozoans

Fungi cells contain a nucleus (eukaryotic) secrete digestive enzymes and absorb the molecules released Heterotrophs (no chloroplasts) Examples: mushrooms, molds, yeast

Plantae cells contain a nucleus (eukaryotic) multicellular; specialized tissues Autotrophs (produce their food) Examples: mosses, ferns, coniferous trees, flowering plants

Animalia cells contain a nucleus (eukaryotic) multicellular; specialized tissues Heterotrophs (ingest their food) Examples: insects, mammals, birds, reptiles

The Levels of Classification There are 8 separate levels of classification These 8 levels are, from most inclusive to most exclusive: Domain  Kingdom  Phylum  Class  Order  Family  Genus  Species This system (minus the Domain classification) was developed by Carolus Linnaeus

To distinguish among groups that had similar characteristics Carolus Linnaeus subdivided each category into smaller and smaller groups of more and more similar organisms by using simple physical characteristics to categorize and describe organisms. At each level of organization, there are more and more similarities among members of the group.

Acronyms King Philip Came Out For Great Soup Kingdom, Phylum, Class, Order, Family, Genus, Species King Philip Came Out For Great Soup Karen Played Checkers Over Four Green Slugs Kids Put Cheese On Fried Golden Slices Ex.

Group domain – Eukarya kingdom – Animalia phylum – Chordata class – Mammalia order – Carnivora family – Felidae genus – Lynx species - rufus

Naming Systems Binomial nomenclature, or a two-name or binomial system is used for naming organisms first word is the genus (capitalized) second is the species These names are recorded in Latin and occasionally Greek (consistent regardless of the language)

Binomial Nomenclature Based on last 2 categories Genus species Purple hydrangea – Hydrangea macrophylla Green brittle star - Ophiarachna incrassata Peacock spider - Maratus volans

Lets put the whole thing together: Classifying the Human Domain: Eukarya Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: sapiens

Changing Names With ability to genetically sequence the DNA now can verify classification Ex. Skunks recently removed from family that contains weasels. Now placed in their own family

WITHOUT LOOKING AT YOUR NOTES: What are the 3 Domains of classification and one thing about each? List the classification categories in order.

Dichotomous Keys Dichotomous Key: Identification key that uses observable characteristics to identify organisms through a series of steps. Two statements are given at each step. A dichotomous key is a tool that allows the user to determine the identity of items in the natural world based on the items characteristics "Dichotomous" means “divided into two parts” Greek origin dichotomous keys always give two distinct choices in each step, often they are opposites Black/white; good/evil; pointed/rounded

Here are creatures we don’t know! How to use a Dichotomous Key? Here are creatures we don’t know! Lets choose one 27

How to use a Dichotomous Key? Choose only one creature at a time. 28

Decide which statement is true How to use a Dichotomous Key? Read steps 1a and 1b Decide which statement is true 1b is true

Then follow the directions after that step. How to use a Dichotomous Key? Then follow the directions after that step. Go to step 5!

At choice 5, you make another dichotomous choice How to use a Dichotomous Key? At choice 5, you make another dichotomous choice 5a is true Go to step 6!

C How to use a Dichotomous Key? Keep going until you come to a step that gives you the creature’s name. 6 a. The creature has one antennae Go to Step 7. C

How to use a Dichotomous Key? Choose a new creature and start at step 1a and 1b again. Continue until you find the creature’s name. C Where do you start Again?

1. a. wings covered by an exoskeleton – go to step 2 b. wings freely observed – Go to step 3 2. a. body has a round shape ……….ladybug, a red beetle with black spots b. body has an elongated shape ……….grasshopper, a green insect that hops 3. a. wings point out from the side of the body ……….dragonfly, an insect that is 10- 15 cm long and lives in marshes b. wings point to the posterior of the body ……….housefly, a flying insect with red eyes and an annoying buzz

What if I Needed to Make a Key: - Use constant characteristics rather than variable ones. (Flowers change with the seasons) - Use measurements rather than terms like "large" and "small". Make the choice a positive one - something "is" instead of "is not". - Ex: snake ears are internal only If possible, start both choices of a pair with the same word or item. - the body is “round” vs the body is “square” - Finish the dichotomous key with a full description of the organism

Dichotomous key Another Example of a dichotomous key…

Dichotomous key the dichotomous key can also be expressed in a diagram form