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What does it mean to be
alive?
What makes something
alive?
1. Living things are made up of cells
2. Living things reproduce
3. Living things are based on the genetic code
4. Living things grow and develop
5. Living things obtain and use materials and
energy
§  6. Living things respond to their environment
§  7. Living things maintain a stable internal
environment
§  8. Living things change over time
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Made up of Cells
What is a cell?
§  Smallest structural and functional unit of
life
§  Self contained
§  Unicellular
§  Multicellular
Reproduction
§  Asexual reproduction
Based on a genetic code
§  DNA
§  One parent making a
exact replica
§  Sexual reproduction
§  Two cells unite to
make a new & unique
cell
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Growth and Development
§  Life cycle
§  pattern of growth and change that occurs during the
organism’s lifetime.
§  Development
§  change in which the cells not only increase in
number but also differentiate
Need for material and
energy
How to obtain this energy
§  Necessary for growth, development, &
reproduction
§  Metabolism
§  All chemical reactions in an organism in
which an organism builds up or breaks down
materials
Autotroph/Producer
Heterotroph/Primary Consumer
Heterotroph/Secondary Consumer
Response to environment
§  Organism must react to the demands of the
environment
§  External stimulus
§  Internal stimulus
Saprobe/Decomposer
Maintaining internal
balance
§  Homeostasis
§  Homeo = same
§  Stasis = stop or slow
§  Maintaining a stable internal condition
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Changing over time
Branches of biology
§  As a group (species) the organism can
change over time. This is evolution.
§  Evolution may be necessary to ensure
the survival of the species.
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Botanist
Zoologist
Microbiologist
Biochemist
Ecologist
Ethologist
Paleontologist
Immunologist
Cytologist
Geneticists
Applied science
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Levels of organization
Physicians
Researchers
Wildlife manager
Veterinarian
etc
Biosphere
Ecosystem
What to listen for….
Community
Population
Organism
System
Organ
Tissue
§  8 Characteristics of living
things
§  Definition of a cell
§  Unicellular vs. multicellular
§  Asexual vs. sexual
reproduction
§  Metabolism
§  Autotroph/producer
§  Heterotroph/1° & 2° consumer
§  Saprobe/decomposer
§  External vs. internal stimuli
§  Homeostasis
§  Levels of organization
Cell
Molecule
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