1. Cellular Organization
Five Levels of Organization
Within the Human Body

2. The Benefits of Being Multicellular
Larger size
The larger you are, the less predators you have, and you can eat larger prey!
Longer life
Longer life-span than unicellular organisms.
Specialization
Each type of cell has a particular job.
This makes the organism more efficient.

3. Levels of Organization
From smallest to largest:
Cells
Tissues
Organs
Organ systems
Organism

4. Cells
Cell – basic unit of structure and function in a living thing

5. Tissues
Tissue – group of similar cells that perform the same function.
Most animals (including humans) have four basic types of tissue:
Muscle tissue
Nerve tissue
Connective tissue
Protective tissue

6. Muscle Tissue
Muscle tissue – makes parts of your body move by contacting (or shortening)

7. Nerve Tissue
Nerve tissue – carries messages back and forth between the brain and every other part of the body.

8. Connective Tissue
Connective Tissue – provides support for your body and connects all its parts.
Ex:
Bone – supports & protects
Fat – insulation & energy storage
Blood

9. Protective Tissue
Also known as epithelial tissue – covers the surfaces of your body (inside & out).

10. Plant Tissues Plants have three types of tissues:
Transport tissue - moves water and nutrients throughout the plant
Protective tissue – covers the plant; helps the plant retain water & protects it from damage
Ground tissue – tissue where photosynthesis occurs

11. Organs
Organ – structure composed of different kinds of tissue working together
Each organ performs a specific job.
Ex:
Heart – pumps blood throughout the body
Stomach – breaks down food so that it can be absorbed by the intestines.

12. Organ Systems
Organ system – a group of organs that work together to perform a major function.
Ex:
Circulatory system – heart, blood vessels, blood

14. Organism
Organism - a living thing

15. Structure & Function
Structure - the arrangement of parts in an organism
Includes the shape of a part and the material from which it is made.
Function - the job the part does
Ex: structure of lungs (spongy sac) is related to its function

16. Homeostasis
The different organ systems work together and depend on one another.
Ex:
Respiratory, digestive & circulatory systems work together to fuel muscles with the energy they need.
The systems of the human body work together to maintain homeostasis.