IB Biology HL 1 Mrs. Peters Fall 2014

Organization of Living Things Cells: either unicellular or multicellular Tissues: only in multicellular organisms, made up of layers of specialized cells Organs: only in multicellular organisms, made up of layers of specialized tissues Organ Systems: only in multicellular organisms, several organs work together to form a system Organisms: can be made up of one cell or of many cells with organ systems

Types of Cells Prokaryotes Eukaryotes  General Characteristics: Unicellular No membrane bound organelles No true nucleus  Types: Bacteria General Characteristics: Unicellular or multicellular Membrane bound Organelles True Nucleus Types: Plant, Animal, Fungi (don’t need to worry about Fungi!)

U6. Cell Differentiation Differentiation: Cells develop to perform different functions All cells have all genetic information (DNA) in the nucleus Each cell type uses only some of the genes Genes being used are expressed.

Types of Animal Cells Stem Cells have the ability to differentiate 2 Types: Embryonic and Adult Tissue Cells Differentiated to form different types of tissues 4 types: connective, epithelial, muscle, nervous

Types of Tissue Cells Epithelial Cells: cover the outside of the body and lines organs and cavities within the body Skin, glands

Types of Tissue Cells Connective Cells: bind and support other tissues Bones, blood, adipose (fat)

Types of Tissue Cells Muscle Cells: long cells capable of contracting when stimulated Skeletal, cardiac, smooth

Types of Tissue Cells Nervous Cells: transmit signals from one part of the animal to another