Study of Biology
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What is Biology?
Biology is the study of all living
things
Living things are called
organisms
Organisms include bacteria,
protists, fungi, plants, & animals
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All Living Things Share
Common Characteristics
1. Basic Unit is the Cell
2. They Reproduce
3. All Based On Universal
Genetic Code (DNA)
4. Grow & Develop
3
Common Characteristics
5. Obtain & Use Materials &
Energy
6. Respond To Their Environment
7. Maintain A Stable Internal
Environment
8. AS A GROUP, Living Things
Evolve, That Is They Change
Over Time
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Characteristics of Organisms
5
All Organisms are
made of Cells
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Facts About Cells
Cells are the smallest living unit
of an organism
All cells contain living material
called cytoplasm
All cells are surrounded by a cell
membrane that controls what
enters & leaves the cell
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More Cell Facts
Cells are complex &
highly organized
Cells have parts called
organelles that do
different jobs
e.g. Chloroplasts in
plants make sugars
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More Cell Facts
The simplest cells are
called Prokaryotes
These cells DO NOT
have a nucleus or
membrane-bound
organelles
Bacteria are examples
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More Cell Facts
More complex cells
are called
Eukaryotes
These cells DO have
a nucleus and
membrane-bound
organelles
Plants, animals, &
fungi are examples
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Organisms are Grouped by
their Number of Cells
Unicellular Organisms
– Living Organism Made Up Of One
Cell
Multicellular Organisms
– Living Organism Made Up Of
Many, Specialized Cells
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Organisms Reproduce to
Pass on their Genetic
Traits
12
Two Types of Reproduction
Sexual
Reproduction
Involves 2 parents
Egg fertilized by
sperm to make a
ZYGOTE
Offspring
DIFFERENT from
parents
13
Two Types of Reproduction
Asexual
Reproduction
Involves a single
organism or cell
Cell divides
Offspring
IDENTICAL to
parent
14
Cells Have a Genetic Code
15
Genetic Code
DNA (deoxyribose nucleic acid)
carries the genetic code for all
organisms
All organisms contain DNA
DNA codes for the proteins that
make up cells & do all the work
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Organisms Grow & Develop
17
Growth & Development
Organisms grow by
producing MORE
CELLS & by cell
ENLARGEMENT
Organisms develop as
they mature into an
adult organism
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Cells Require Food & Energy
19
Food Requirements
Autotrophs can make
their own food
Photoautotrophs use
sunlight to make food
(photosynthesis)
Chemoautotrophs use
chemicals such as iron
& sulfur as their
energy
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Food Requirements
Heterotrophs can NOT make their
own food
They must consume other
organisms
Herbivores eat plants
Carnivores eat meat
Omnivores eat plants & animals
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Metabolism
Sum of all the chemical reactions
in an organism
All require energy
Sunlight is the ultimate energy
for life on Earth
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Metabolism
Cellular Respiration
– Cells releasing the chemical
energy stored in foods
6O2 + C6H12O6
6CO2 + 6H2O
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Organisms Respond to
Stimuli
Organisms Respond to
Temperature, Water, Food
Supplies, etc. In Order To
Survive & Reproduce
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Homeostasis
Keeping The Internal Environment
Of The Cell or Organism Within
The Ranges Required For Life
Stable internal conditions of pH,
temperature, water balance, etc.
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Living Things Evolve
Groups Of Organisms
(Not Individuals)
Change Over Time In
Order To Survive
Within Changing
Environments.
Fossil records show
changes in groups of
organisms
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Life is Organized on
Several Levels
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Levels
Atoms
Molecules
Organelles
Cells – life starts here
Tissues
Organs
System
Organism
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Levels
Population
Community
Ecosystem
Biosphere
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