1. Biology: the study of living things

2. Characteristics of Life
Made of cells
Cell: basic unit of life
Unicellular organisms consist of a single cell
Multicellular organisms consist of a collection of specialized cells

3. Characteristics of Life
Reproduce
Sexual: two cells from parents unite to form a new, unique organism
Asexual: organism splits to form two identical organisms
Based on a universal genetic code
The same chemical code determines the traits of all life on Earth

4. Characteristics of Life
Grow & develop
Have a distinctive life cycle
Need energy
Autotrophs: make energy from the sun (plants)
Heterotrophs: eat other organisms (animals, fungi)

5. Characteristics of Life
Respond to the environment
Maintain an internal balance
Homeostasis: keeping internal conditions relatively stable -- i.e. temperature, pH, oxygen levels, blood sugar, etc.
Evolve
As a group, organisms change over time to better fit their environments
Change is necessary for survival in an ever-changing world.

6. You can’t study living things without taking into account the living and non-living aspects of their environment.
Biotic: living--once living--organic
Animals, plants, fungi, bacteria, etc.
Abiotic: nonliving--not of life--inorganic
Oxygen, carbon, water, climate/weather, wind, sunlight temperature