CELL DIFFERENTIATIONSection 10.4

From one cell to many• Each of us started life as one cell

• Living things pass through a developmental stage called an embryo

• During the develop process cells become more and more differentiated and specialized for particular functions

• Differentiation = the process in which cells become specialized• Specialized to perform certain tasks

Mapping Differentiation• The process of differentiation determines the cells

ultimate identify• Will it be a nerve cell or a muscle cell

• Scientist have been able to map out each and every cell division on a microscopic worm C. elegans

Stem cells and development• Totipotent = cells that are able to do everything, to develop

into any type of cell in the body

Human Development• After 4 days of development the embryo forms a blastocyst

• Blastocyst = A hollow ball of cells with a cluster of cells inside known as the inner cell mass• Cells have already begun to specialize

• Outer cells – attach embryo to its mother• Inner cells – cells that become the embryo

• Pluripotent = cell that can develop into most of the body’s cell types

Stem cells • Unspecialized cells which differentiated cells develop

• 2 types of stem cells• 1. Embryonic stem cells – found in early embryos• 2. Adult stem cells – limited life span and need to be constantly

replaced• Example: skin or blood

• Multipotent = adult stem cells that can develop into many types of differentiated cells • Example: blood cells