Characteristics of Life Study Notes:
Identify the 5 main characteristics of life:
1.
2.
3.
4.
5.
Contain one or more cells
Ability to reproduce
Growth and development
Obtain and use energy
Respond to environment/ maintain homeostasis
1. Contain one or more cells:
a. Cells: simplest level of life
b. Cells perform various functions
c. Cell membrane separates cells from the environment
d. Multicellular organisms are made of many cells (example)
e. Unicellular organisms are made of one cell (example)
2. Ability to reproduce
a. Reproduction is the production of offpring
b. Reproduction is necessary for the survival of a population BUT not an individual
c. Two types of reproduction
i. Sexual- sperm and egg
ii. Asexual – a single organism can reproduce without the aid of another
3. Growth and development
a. All organisms begin as a single cell
b. Growth results in an increase in amount of living materials
c. Development is going through many changes
4. Obtain and use Energy
a. Autotroph – make their own food and obtain their energy from that
b. Heterotroph – obtain energy from food that they eat
5. Respond to Environment/ Stimuli
a. Homeostasis- enables organisms to regulate internal environments despite
changes in external environment
b. Stimuli vs. response examples
c. Living vs. non-living