WARM UP 9/15/09 True or False? – answer in notebook 1.If it moves it is alive 2.If it seems to move by itself, it’s alive; if it’s moved by something else, it’s not alive. 3.If it makes light or noise it is alive 4.It’s not alive unless it is doing something 4.To be alive, it must breathe 5.Not all living things grow 6.Bacteria and fungi are not living things 7.Plants have a completely different kind of life than animals

Characteristics of Living Things What is Life? Define life? Is this a living thing? an organism? Origin?... Spontaneous generation/abiogensis or biogenesis?

No one definitive list:  Organized  Reproduce  Responds to stimuli  Requires water and energy  Adaptation  Grow and Develop  Maintain homeostasis

Organization  One or more cells –unicellular, multicellular  Cells contain DNA molecules = heredity  Common set of compounds –organic molecules = carbon & hydrogen  Simple to complex – at all levels  Maintain and repair structure atoms tissues cells compounds molecules organs organ systems organisms populations communities ecosystems biosphere

Reproduction  Marks a successful life  Continues the species  Group of organisms that can interbreed and produce fertile offspring  Pass on genes / DNA  Sexual and/or asexual

Respond to stimuli  Possess “irritability” – able to respond  Stimulus must be strong enough to elicit a response  Must respond to environmental stimuli to survive and/or reproduce  Homeostasis – maintain internal conditions or environment  By internal feedback systems – communicate

ENERGY REQUIRED  Ultimate source is the sun  To maintain other characteristics and stay alive;  Must be obtained – ingested or absorbed; converted to a usable form  May be transformed and transferred but never created or destroyed  Respiration – exchange gases with environment  Require water for chemical reactions  METABOLISM –sum of all chemical reactions and energy exchange within an organism  Anabolic reactions – build up; simple >> complex  Catabolic reactions – break down; complex >> simple

Change over time  Growth – increase in size  Develop – change in abilities; + / -  Die – limited lifespans

Adaptation  Inherited structure, behavior or internal process that enables organism to respond to environmental factors and live successfully  Only an adaptation if inheritable  Must match environment  Gradual accumulation of adaptations result in evolution  Result of mutation – not intentional  Must be able to be passed along  Able to move in some manner to meet needs

All living things…  Have every characteristic at some time in their life  Similar in the variety of processes they carry out  May be in a state of dormancy  Individual does not have to reproduce to survive – but species must!