Target: To understand what differentiation is and what factors influence how and when cells differentiate within different organisms

- process by which cells change in structure and become capable of carrying out specialized functions - as cells differentiate, they become different from one another - together, the specialized cells join and form tissue, then organs, then organ systems

Structure Difference - multicellular organisms start life as one cell. From mitosis & differentiation, single cells become organisms with specialized structures

- as cell structure begins to differentiate, their jobs change. Ex: plant leaf cells vs plant root cells; leaf cells will have chloroplasts to capture sunlight, root cells will have fingerlike projections to absorb water from soil

Tissue, Organs & Organ Systems - Cells organize when they differentiate - Ex: muscle cells organize into muscle tissue. Groups of tissues form organs, such as stomach, then organs & tissues combine for system, such as digestive system.

DNA guides the cell as to what it will differentiate to - once a cell’s future is determined, when & how much it changes depends on its DNA, function, & type of organism

Some cell’s differentiate during development, others not until later in life as an organism

Stem Cells – how animal cells differentiate - cells that can differentiate throughout life - exist throughout body - respond to specific needs in body by becoming specialized. Ex: stem cells produce red & white blood cells, as well as platelets

 Plant cells can differentiate, increase the root & stem size. Ex: a plant is cut & put into soil or water, stem begins to grow. Soon, cells will differentiate into root cells & stem cells, and grow a new plant.