Taxonomy & Classification Complete “what do you know about classification? Turn In

What am I doing today Learning how to use a dichotomous key Learning how to read a Cladogram Learning what is the significance of each clade

What am I doing today? Dichotomous Keys- a chart that uses a series of choice to help you identify organisms At each step in a dichotomous key you will have 2 choices! (di- means two)

Lets Practice Dichotomous Keys Using Smiley Faces-

Let’s Review Why Do Scientist Classify? Because they work with a diversity of life Classification-organizes organisms in a logical manner Allows the to -Assign a universal accepted name to each organism

Biological Classification Aristotle was one of the first people to classify living organisms According to physical characteristics Very broad grouping Carolus Linnaeus developed a system of naming that we still use today According to Morphology This system is called Binomial Nomenclature (two name naming system)

Binomial Nomenclature Each organism has a two part name 1. The genus is the first name and is ALWAYS capitalized 2. The species is the second part of the name and is lower case 3. Both names are either underlined or italicized 4. Example: Human = Homo sapien Homo = the genus sapien= species

Linnaeus Grouped them according to the body structures they shared 1. The groups are called taxa 2. The smallest taxa is the species Taxonomy: the science of naming organisms

The system of grouping organisms is as follows: 1. Kingdom 2. Phylum 3. Class 4. Order 5. Family 6. Genus 7. Species Human Classification 1. Kingdom – Animalia 2. Phylum – Chordata 3. Class – Mammalia 4. Order – Primates 5. Family – Hominidia 6. Genus – Homo 7. Species - sapien

Bigger Than Kingdoms 3 Domains to classify organisms under: Archaea: includes the kingdom Archaeabacteria Bacteria: includes the kingdom Eubacteria Eukarya: includes the kingdoms protista, fungi, plantae, animalia

There are 6 Kingdoms! 1. Archaeabacteria- ancient bacteria that live in extreme environments 2. Eubacteria- bacteria and blue-green algae 3. Protista- paramecium, amoeba, euglena, volvox and sprirogyra 4. Fungi- mushrooms and yeast 5. Plantae- plants 6. Animalia- vertebrates (backbone) & invertebrates (no backbone)

Viruses: The Exception Viruses are NOT living so they don’t fit into any kingdom Made of a protein coat called a capsid and nucleic acid (DNA or RNA) Example of a virus = bacteriophage Bacteriophages attack bacteria

More on Viruses Viruses are pathogens (disease causing) Specific viruses affect specific organisms (hosts) Ex. A plant virus can’t infect an animal unless it mutates (Avian Flu) Bird Flu

Life Cycle of a Virus In order to reproduce, viruses must invade or infect a living host cell 1. Start of infection: virus DNA enters the host cell (protein coat does not) 2. Virus enzymes destroy the hosts DNA but not it’s own. 3. Replication: virus makes copies of itself A. can occur as fast as 25 minutes depending on the virus 4. The infected cell bursts and releases hundreds of virus particles that infect other cells

Let’s Review Viruses c. Construct an argument supported by empirical evidence to compare and contrast the characteristics of viruses and organisms.  Use evidence to support your position on the “classification” of viruses (living or non-living)  Compare and contrast Viruses to Bacteria;

Let’s Review Viruses Chapter 18 Page Questions 1-4 and c. Construct an argument supported by empirical evidence to compare and contrast the characteristics of viruses and organisms.  Use evidence to support your position on the “classification” of viruses (living or non-living)  Compare and contrast Viruses to Bacteria; Chapter 18 Page Questions 1-4 and Chapter Review 21-27 Viruses vs. Bacteria

Let’s Review Viruses Chapter 18 Page Questions 1-4 and c. Construct an argument supported by empirical evidence to compare and contrast the characteristics of viruses and organisms.  Use evidence to support your position on the “classification” of viruses (living or non-living)  Compare and contrast Viruses to Bacteria; Chapter 18 Page Questions 1-4 and Chapter Review 21-27 Viruses vs. Bacteria

Animal Symmetry Radial Symmetry- simplest animals have this No real head Many are sessile (don’t move) Body parts repeat around an imaginary line drawn through the center of the body

Bilateral Symmetry More complex animals have this Body parts repeat on either side of an imaginary line drawn down the middle of the body One side is the mirror image of the other

Animals with bilateral symmetry have front and back ends Anterior- front end Posterior- back end Dorsal- upper side Ventral- lower side

Cephalization a concentration of organs and nerve cells in their head region Most animals have this characteristic