1. Levels of Organization & Homeostasis

2. Multi-celled Organisms
Organisms like humans are made of many cells.
Cells have different functions (specialized cells that work together)

3. Determination
Stem cells are the first cells present in a developing embryo
Have the ability to become any type of specialized cell

4. Differentiation
Committed cells develop specialized structures to help them do their jobs
Genes are turned on or off
Ex: neurons form dendrites

5. 5 levels of organization in multi-cellular organisms:
Cells – smallest unit of life
Tissues – made of lots of similar cells
Organs – made of tissues
Systems – organs that work together
Organisms – organ systems work together to perform all functions

7. Tissue – A group of cells working together

8. Tissues There are 4 types of tissues in the human body.
Muscle Tissue - movement
Nervous Tissue – send messages
Connective Tissue - supports the body and connects its parts
Epithelial Tissue – covers external and internal surfaces

9. Different tissues make different organs.
All perform specific functions and work together to maintain homeostasis

10. Homeostasis
Homeostasis – maintaining stable internal conditions even when external conditions are changing
Examples –
Regulation of body temperature (sweating, goose bumps)
Maintain proper hydration (feeling thirsty)

11. Examples of Homeostasis
Regulation of body temperature (sweating, goose bumps)

12. Examples of Homeostasis
Maintain proper hydration (feeling thirsty)

13. Feedback Loops
The body uses feedback loops to bring levels back to set point
Negative – reverses the change to bring conditions back to set point (sweating to reduce body temp)
Positive – increases change away from set point (release of hormones during puberty)