What is Life Characteristics Cellular Organization Energy Use

What is Life?

Characteristics • • • Cellular Organization Energy Use Growth and Development Response to Stimuli Reproduction

Cellular Organization • All living things are made of cells. • Unicellular organisms are made of one cell. • Multicellular organisms have specialized cells.

Energy Use • All organisms use energy for life processes. • Organisms that get their energy directly from the sun are autotrophs. (Capable of Photosynthesis) • Organisms that eat autotrophs or other heterotrophs for their stored energy are heterotrophs.

Growth and Development • Growth is becoming larger • Development is process of change that makes a more complex organism.

Respond to Stimuli • Include changes in temperature, light , sound and other factors • Example: Plants respond to gravity and grow against it.

Reproduction • Produce offspring similar to themselves.

Needs • Water • Living Space • Stable Internal Conditions

Water • Dissolves other chemicals. • Medium for chemical reactions. • Transportation for chemicals.

Living Space • Some organisms like plants have to compete for space.

Stable Internal Conditions • The maintenance of stable internal conditions despite changes in the surroundings is called homeostasis. • Maintaining Body temperature is an example of homeostasis.