1. Cell Specialization

2. Unicellular Organism
consists of only one cell
that one cell carries out all functions required to maintain the life of the organism
So, NO cell specialization

3. Multicellular Organism
consists of more than one cell
cells are specialized to perform certain functions
Cells develop differently (differentiation) and become specialized for their function (cell specialization)

4. Examples of Cell Specialization In Multicellular Organisms
Neuron (nerve cell)
- sends info from one part of the body to another
- very long and thin

5. Red Blood Cells
- carry oxygen throughout body
- flattened disks so that they can easily flow through blood vessels

6. Sperm Cell
- fertilizes egg
- strong tail for quick swimming, distinct head for entering egg cell

7. Cell differentiation is a result of different gene expression, a process in which a gene is switched on & begins production of its protein.

8. Most cells in your body have the same DNA
Cells use only the DNA that they need; the rest is inactive
For example, skin cells use the DNA that codes for melanin (a skin pigment that protects from UV light)
Heart cells do not need melanin, so it is “turned off” in heart cells