1. Characteristics of Life

2. Objectives

3. Characteristics of Life
There is no one definition of life that is accepted by scientists.
However, life is defined by the properties and functions characteristic of living things
Life Functions {Properties of Life} are the various activities carried on by living things.

4. Properties of Life Order Reproduction Growth and Development
Nutrition
Energy Utilization
Respiration
Response to Stimuli

5. Order
All other characteristics of life emerge from an organism’s complex organization
Made up of cells
A single cell can be an organism
Bacteria
Unicellular
Most organisms are multicellular

6. Energy Utilization Energy is used to grow, develop and reproduce
Anabolism
Process in a living thing that involves putting things together, or synthesizing complex substances from simpler substances
Photosynthesis
Photo = Light
Synthesis = put together

7. Energy Utilization #2 Catabolism Metabolism
Changing complex substances into simpler ones
Results in a release of energy
Can animals perform photosynthesis?
Metabolism
The total sum of all chemical reactions in the body
The balance of anabolism and catabolism

8. Growth and Development
Growth involves the increase in cell number and cell size
What growth spurt are you going through right now?
When does an organism stop growing/developing?
What tells our body that it is time for a cell to die?
How often do humans replace every cell in their body?
Growth-->Aging-->Death
How can you tell when a tree has died?`

9. Reproduction New cells arising from preexisting cells
Organisms can reproduce their own kind
Produce organisms of the same “type”
Species
Sexual Reproduction
Asexual Reproduction
2 Cells combining to produce the first cell of a new organism
Single organism that can reproduce without the aid of another

10. Plants Dicots Plants contain both sperm and eggs Fertilization
Located in the flower of the plant
Fertilization
Self Pollination
The sperm fertilizes the egg of the same plant
Cross Pollination
The sperm of Plant A fertilizes the sperm of Plant B

11. Response to Stimuli/Environment
Involves behaviors, metabolism and growth
What are some environmental pressures that you, as a human, respond to?
Light, temperature, odor, sound, gravity, heat, water and pressure

12. Response to Stimuli/Environment II
Is it always hot in Florida?
What does your body do to cool off?
Sweat--Brain perceives that you are losing water--Become thirsty

13. Response to Stimuli/Environment III
Homeostasis
Process by which organisms respond to stimuli in ways that keep their body suitable for life
Refers to an organism’s ability to maintain a constant or stable condition
Regulation mechanism to maintain an organisms internal environment
Provides capacity to evolve--”micro-evolution”
What household appliance provides a great example of homeostasis?