Chapter 1 section 4 (how are living things classified) 2011

Chapter 1: Nature of Science

Section 4:Classifying and Diverstiy

A. Why we need to Classify organisms 1. Hundreds of new organisms are discovered and

named each year. 2. Most of the new discoveries are INSECTS. 3. Most are found in the tropical rain forest.

B. History of Classification 1. Classify: to group things based on similarities.

a. Example: Grocery aisles are grouped by the type of food they stock.

b. Libraries: Books are grouped together by type. c. Music Stores: Group CD’s by type of music.

2. Aristotle was the first person to classify living things. a. He developed a science of classifying and naming

organisms called TAXONOMY. b. Divided living things into two groups called

KINGDOMS. c. KINGDOM: Largest of all the taxonomic categories. d. Two groups were called Plants and Animals.

3. Aristotle used two main characteristics (color and movement) to figure out which kingdom the organism should be placed.

a. If it was green and did not move it was a plant. b. If it wasn’t green and moved it was an animal.

DO YOU SEE ANY POSSIBLE PROBLEMS WITH ARISTOTLE’S CLASSIFICATION SYSTEM? (Think about a grasshopper, a frog, red maple trees, etc….)

4. Aristotle’s Plant Kingdom a. Subgroup Herbs: small plants b. Subgroup Shrubs: medium plants c. Subgroup Trees: large plants.

5. Aristotle’s Animal Kingdoms a. Subgroup Avian: air animals b. Subgroup Aquatic: water animals c. Subgroup Terrestrial: Land Animals

C. Problems with Aristotle’s Classification 1. Some organisms cannot be classified by his

taxonomic characteristics. a. Frogs: They are green and they moved!!! b. Red Maple Trees: They are red and did not move (like

people; we know plants do move toward the sun) c. Ducks: fly through the air, float on water, and nest on

land.

2. Because of these problems; improvements had to be made.

D. Carolus Linnaeus (Swedish Naturalist) 1. Linnaeus created a better system to classify

organisms. a. His system was based on similarities in body structure

and systems, size, shape, color, and the method of obtaining food.

2. Linnaeus also created a system for naming organisms.

a. BINOMIAL NOMENCLATURE: 2 word naming system used to name all organisms.

b. BINOMIAL NOMENCLATURE is still used today c. This is also called the Scientific Name

3. Scientific Name has two parts a. First word is called the GENUS. b. The second word is called the SPECIES.

E. Rules of Binomial Nomenclature 1. Genus always comes first, is always capitalized, and

either italicized or underlined. 2. The Species always is second, is always lowercase,

and either italicized or underlined. 3. Scientific names are always written in Latin; all

educated people worldwide used to speak Latin.

4. Examples of Scientific Names a. Scientific Names b. Canis familiaris-dog c. Felis domesticus-cat d. Homo sapiens-humans e. Canis Lupus- Wolf

f. All the different breeds of dogs are all Canis familiaris; therefore they can interbreed (Mutt)

5. Only organisms of the same SPECIES can successfully reproduce without any problems.

a. Horse X Donkey= Mule (cannot reproduce) b. Lion X Tiger= Liger c. Zebra and Donkey= Zedonk d. ***Naming these organisms is tricky, you would use

the genus name of the parents then both species names of the parents: Mule (Equus caballus x asinus)

Liger Link

F. How Do We Classify today? 1. Based on the following

a. Presence of a nucleus b. How many cells are present. c. Ability to make food. d. Ability to move. e. DNA f. Body Structure (how may legs, arm, lungs, etc.) g. Phylogeny

2. Phylogeny is the organism’s evolutionary history.

G. Taxonomic Groups (From largest to smallest)

Kingdom Phylum

Class Order

Family Genus

Species

H. The Six Kingdoms Used Today 1. Archaebacteria

a. Once celled bacteria that live in extreme environments, like salt water, volcanoes, and sulfur springs.

b. Prokaryotes: does not have a true nucleus, DNA is there bit it is not surrounded by a membrane.

c. Some make own food, some do not.

Prokaryote vs. Eukaryote

2. Eubacteria a. One celled bacteria that live in normal environments. b. Prokaryotes (does not have a true nucleus) c. Example: Streptococcus, cyanobacteria (green), E. Coli

3. Protista a. 1 or many celled b. Most live in water c. Eukaryotic (has a true nucleus) d. Examples: (paramecium, Amoeba, Euglena)

4. Fungi a. Have one or many cells b. Eukaryotic (has a true nucleus) c. Examples: Mushrooms, molds, yeasts

5. Plants a. Many celled organisms b. Eukaryotic (has a true nuclues) c. Examples: Roses, Grass, Apple Tree, Moss

6. Animal Kingdom a. Many celled b. Most advanced kingdom c. Eukaryotic : has a true nucleus, membrane

surrounds genetic material. d. Examples: Humans, monkeys, sponges, ect.

I. Ways Organisms Obtain Food 1. Producers: can make their own food by

photosynthesis. a. Example: Plants, green bacteria, green protists

2. Consumers: Cannot make their own food; must go out and get it from another organism.

3. Types of Consumers a. Parasites: Feed off another living thing; usually harsm

the host. (fleas, ticks, leeches) (see previous slide for pic)

b. Decomposer (Saprophyte): Feed off of already dead things. (humans, flies, crows, turkey vultures)

c. Predator: Hunts, kills, and eats its prey immediately. (Tigers, Grizzly Bears, Eagles, Red Tailed Hawks)

J. Summary of Classification 1. 1.5 million species have been identified. 2. Scientists believe there are between 5 to 30

million species on Earth. 3. Aristotle started out with 2 (Plant/Animal) 4. Invention of microscope led to a third kingdom

(Protist). 5. More studies led to 5 kingdoms (Plant, Animal,

Fungi, Protist, and Bacteria {Monera}) 6. Today there are 6; Bacteria is now broken into

Archaebacteria and Eubacteria. 7. Is there a 7th in the future??? (Viruses????)

K. Species Diversity 1. Diversity: Great variety of plants, animals, and

other species living in an area. a. More diverse an area, the more stable it is.

2. In 1 hectare (50 acres) of the Rain Forest there are around 200 species of plants and 1000 species of animals. (Wow!!!!) a. This region has excellent diversity. b. Unfortunately we are cutting down about 1000 acres

of rain forest every minute!!!!!

L. Extinction 1. Extinction: when a species no longer exists. 2. Examples:

a. Dodo bird b. Passenger Pigeon c. Tasmanian Wolf d. Carolina Parakeet e. Dinosaurs

M. What Does Endangered Mean? 1. Endangered: Animals that are close to becoming

extinct. 2. Examples:

a. Florida Panther b. Bog Turtle c. Gray Wolf d. Manatee

N. Common Names 1. Scientists do not use common names because

they can be very confusing; often there are many names for the same organism.

2. Examples: a. Groundhog and Woodchuck b. Puma, Cougar, and Mountain Lion (depending upon

location)

3. Because of this scientists only use scientific names.

O. Tools for Identifying Organisms 1. Field Guide: Book of traits and pictures to

identify organisms. 2. Dichotomous Keys: a detailed list of traits used

to classify organisms. (we will do an activity on this!!!)