Cell Diversity

Types of Organisms Unicellular – composed of a single cell   Multicellular – composed of many cells

Prokaryotic Cells Simple cells Single celled organisms Examples: bacteria and blue green algae No Nucleus No membrane bound organelles DNA Circular segment of DNA in cytoplasm

Eukaryotic Cells More complex Single celled (protist) Multicellular (protist, fungi, plant, aniaml) Well defined nucleus Membrane bound organelles DNA as chromosomes in the nucleus

Eukaryotic Cells How did eukaryotic cells form? Prokaryotic cells began evolving internal membranes Some prokaryotic organisms were engulfed or consumed by others Became symbiotic inclusions in the bigger cells Eventually evolved into organelles like mitochondria and chloroplasts (endosymbiotic theory) How did eukaryotic cells form? 1 2 3 4 5

Types of Cells Both Prokaryote Eukaryote Have a nucleus Unicellular No Nucleus Lack major organelles Have cell membrane Contain DNA Have a nucleus Contain organelles

http://www.youtube.com/watch?v=gfzVW G2DnQ4&feature=related

Cell Specialization Cell specialization – cells do different tasks

Levels of Organization Within a multicellular organism, there are different levels of organization Cell Tissue - Group of similar cells that perform a particular function Organ - Group of similar tissues that perform a particular function Organ System - Group of organs that work together to perform a specific function Organism