Section 2
Life
Book
Version 29
By Boundless
By Boundless
Boundless Anatomy and Physiology
Physiology
by Boundless
3 concepts
![Thumbnail](../../../../../../figures.boundless-cdn.com/6498/square/hoh-rain-forest-trees.jpeg)
Life Functions
All life forms require certain core elements as well as physical and chemical factors from the ecosystem for biochemical functioning.
![Thumbnail](../../../../../../figures.boundless-cdn.com/16518/square/a-child-sleeping.jpeg)
Survival Needs
To sustain human life, certain physiological needs include air, water, food, shelter, sanitation, touch, sleep and personal space.
![Thumbnail](../../../../../../figures.boundless-cdn.com/32096/square/q0vxsubtt4e9uaqkster.jpg)
Levels of Organization
Living organisms are made up of four levels of organization: cells, tissues, organs, and organ systems.