1. KEY CONCEPT The human body has five levels of organization.

2. Specialized cells develop from a single zygote.
Organisms are made up of specialized cells.
red blood cell
nerve cell

3. Zygotes first divide into embryonic stem cells.
Stem cells develop in two stages.
determination, or committing to become one cell type
differentiation, or acquiring specialized structures and functions

4. Specialized cells perform specific tasks.
Specialized cells function together in tissues, organs, organ systems, and the whole organism.
Specialized cells perform specific tasks.
Tissues are groups of similar cells working together.
epithelial tissue
connective tissue
muscle tissue
nervous tissue
cell
tissue

6. Cells are the basic unit of structure and function in living things.
Tissues are a group of similar cells that work together to perform a specific function.
Organs are different tissues working together.
Organ systems are two or more organs working together.
Organism is all organ systems working together.
ORGANS
ORGAN SYSTEM
ORGANISM

7. There are 11 major organ systems in the human body.

8. Ted Ed Video

9. STOP & REVIEW Specialized cells develop from a single _______. zygote
Zygotes first divide into embryonic ____________.
Stem cells
Stem cells develop in two stages.
___________, or committing to become one cell type
determination
____________, or acquiring specialized structures and functions.
differentiation
The five levels of biological organization are (in order)
Cells
Tissue
Organ
Organ System
Organism