Ths general biology unit 2 our bodies living organization notes_v1516

1. BIOLOGY
Unit 2 Notes:
Living
Organization

2. (1) Living Organization
• All living things are made of cells and
atoms/molecules.
• Levels of Organization:
– Atoms
– Cells (Basic units of life.)
– Tissues (Similar cells working on a common function.)
– Organs (Different tissues working on a common function.)
– Organ Systems
(Different organs working on a common function.)
– Organism (All organ systems maintaining homeostasis.)

4. (2) Cell Processes
• All living systems are made of atoms.
• All living things contain at least the following
biological elements:
Carbon, Hydrogen, Oxygen, Nitrogen,
Phosphorus, Sulfur
• All cellular processes are driven by energy
exchange and the movement and reacting of
different molecules.

7. (3) Homeostasis
• Involuntary processes and reactions are in place to
maintain Homeostasis within cells.
• Homeostasis = Internal stability / balance.

8. (4) Cell Specialization
• When cells are “specialized” this means that they
have a unique shape and a unique function.
• In our bodies we have many specialized cells,
which each complete a specific function, to
maintain overall homeostasis.

11. (5) Human Organs
• Humans have a lot of different organs to keep us
living and healthy.
• Some Main Internal Organs:
– Brain
– Heart
– Lungs
– Liver
– Stomach
– Small and Large Intestine
– Kidneys

12. (6) Organ Functions
• Brain: Controls all other organ systems and allows
us to respond.
• Heart: Pumps and circulates blood.
• Lungs: Bring in oxygen gas, and get rid of carbon
dioxide gas.
• Liver: Detoxifies chemicals and breaks down drugs
in blood.

13. Organ Functions Continued
• Stomach: Breaks down food into molecular
components.
• Small Intestine: Finish breaking down food and
absorb useful nutrients.
• Large Intestine: Absorb water, and excrete food
waste.
• Kidneys: Filter blood and maintain blood
homeostasis.