Transcript Characteristics of Living Things

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:
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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
organs
tissues
cells
compounds
organ
systems
organisms
populations
communities
molecules
atoms
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!