1. Cell Diversity
The move from unicellular to multicellular organisms occurred through cell specialization.
The division of required tasks necessary to maintain function of an organism allows for organisms to become larger and more complex
Examples of cell specialization
Blood cells
Nerve cells
Muscle cells
Bone cells
Skin cells …

2. Cell Specialization Cell specialization through induction…
Cell bordering developing cell sends a chemical signal that determines the fate of the developing cell
Blood cells
Red… Accept and transport oxygen
White… Active in the immune response
Nerve cells…
Accept and transmit information
Muscle cells
Allows for movement and tactile response
Bone cells
Gives internal structural support
Skin cells
Forms a protective barrier around the organism

3. Levels of Organization
Cell
Tissue
Group of like cells that perform a particular function
Muscle… contractile unit
Epithelial… lines cavities
Nervous… transmits information
Connective… provides structural support

4. Levels of Organization
Cell
Tissue
Organ
Groups of tissues working together
Lungs
Heart
Skin
Intestines…

5. Levels of Organization
Cell
Tissue
Organ
Organ System
Group of organs working together for a common purpose
Cardiopulmonary system
Heart and Lungs work together to transport oxygen to the tissues of the body