Classification Grouping of different types of organisms based upon similarities in structure and/or presumed evolutionary relationships.

WHY CLASSIFY? In order to more easily study the unity and diversity of living organisms in an organized manner, biologists classify organisms. This means that they group organisms together based on their common characteristics. Physical structure is often the primary basis for biological classification.

Early classification Animals & Plants With the discovery of the microscope in the 1600’s many new organisms were discovered. The microscope was the basis for the change in the classification system.

BIONOMIAL NOMENCLATURE Carolus Linneaus devised binomial nomenclature (naming) Two Latin names: Genus-species Example: scientific name of humans: Homo sapiens Homo is the genus name and sapiens is the species name Both have to be printed in italics or underlined -Genus is ALWAYS capitalized

MODERN CLASSIFICATION SYSTEM: DOMAIN KINGDOM PHYLLUM CLASS ORDER FAMILY GENUS SPECIES Did King Phillip Come Over For Good Soup?

DID KING PHILIP COME OVER FOR GOOD SOUP? REMEMBER: DID KING PHILIP COME OVER FOR GOOD SOUP?

KINGDOMS: The Six Kingdom System is based on the following criteria: 1. Prokaryotic or eukaryotic 2. Unicellular or multicellular 3. Type of nutrition (autotroph or heterotroph) 4. Cell Structure (types of organelles, cell wall, etc.)

Archaebacteria Most primitive and often live in extremely harsh environments Unicellular and no nucleus This is the proposed sixth Kingdom There are 3 types: salt-loving, heat-loving and methane-loving

Kingdom Monera bacteria and blue green algae have a primitive cell structure no organized nucleus or nuclear membrane Three basic types: Coccus = round Bacillus = rod-shaped Spirillum = spiral

Kingdom Protista Predominately unicellular organisms with plant- or animal-like characteristics Examples include protozoa and all algae except the blue-green Have a true nucleus and nuclear membrane Classification of Protists: Most protozoa are motile (can move) and are divided into phyla based on their means of locomotion

Animal-like Protists Plant-like Protists: Often animal-like Protists are called PROTOZOA They can live in fresh or salt water, in the soil, or in the bodies of other organisms Plant-like Protists: Plant-like Protists are commonly called ALGAE They contain chloroplasts and are therefore AUTOTROPHIC

Spirogyra Plant-like Protists that contains thread-like filaments of chloroplasts They may reproduce asexually by MITOSIS or sexually by CONJUGATION

Plant-and Animal-like Protists The Euglena: Exhibits both animal-like and plant-like characteristics Contains chloroplasts, which are involved in PHOTOSYNTHESIS Contains a flagellum, which is used for locomotion Euglena may be autotrophic or heterotrophic depending on the environment In a light environment euglena would be autotrophic In a dark environment the euglena would be heterotrophic

KINGDOM FUNGI Examples include yeasts, molds, and mushrooms Cells are usually organized into branched, multinucleate filaments which absorb digested food from the external environment Mushrooms are made up of a network of tubes called hyphae

Kingdom Plantae Multicellular - possess chloroplasts (for photosynthesis) and cell walls make their own food (autotrophic) Reproduce sexually (can be asexual) Vascular plants are more complex - they have specialized tissues: xylem, which is involved in structural support and water conduction, and phloem, which functions in food conduction Nonvascular plants are usually no more than an inch or two in height because they do not have vascular tissues to give support.

ONION CELLS FROM LAB – NOTE THE BOXY SHAPE OF PLANT CELLS & THE DISTINCT CELL WALL

Kingdom Animalia Multicellular organisms which ingest their food = heterotrophs Reproduce sexually

Viruses Not classified in a kingdom Contain genetic material (DNA) but lack cell structures Only carry on the life function of reproduction They must have a host (another living organism) to be able to reproduce This causes disease in the host (Ex: colds, rabies, AIDS, flu)

Bacteriophages invade the host cell, take over the cell, and begin replicating viruses, eventually lysing or bursting the host cell, releasing the new viruses to infect additional cells Papillomavirus is a DNA virus that causes warts Polio Virus