Download What is an Organism??

BIOLOGY
• BIO = Latin for “LIFE”
OLOGY = From the latin word LOGOS
meaning the “STUDY OF”
Section 2.1
5 Levels of Organization
Biosphere
Ecosystems
Communities
Populations
Organism
BIOSPHERE
Biomes
ECOSYSTEMS
Communities
Populations
Section 2.1
What is an Organism??
Organization Within an Organism
6 CHARACTERISTICS
OF
LIFE
Living things must
possess all these
characteristics in order to
be considered alive
1. Organisms Use Energy
• Every organism uses energy in a process
called Metabolism – All the chemical
reactions that take place inside an
organism.
Autotrophs
Heterotrophs
2. Every living thing
Responds to stimuli
• Changes happen inside and outside of an
organism and an organism needs to
respond appropriately to stay alive.
3. LIFE IS ORGANIZED
• We say that life struggles to keep things
organized. Living things must use energy
to stay organized
• The natural tendency in nature is to
become less organized.
This is why dead things decompose
4. Living things GROW and
DEVELOP
• Growth involves adding more
cells
• Development involves changes in
cell’s structure and function
5. Living Things
Reproduce
• The Individual doesn’t need it to survive
• Species need reproduction to avoid
extinction.
– There are lots of ways to do it
– Sexual vs. Asexual. What does the prefix
mean?
• Gene: short segment of DNA that contains
instructions for a single trait.
6. All living Things are made of
one or more cells
• Unicellular
• Multicellular
Themes of Biology
• Themes are very broad
concepts that connect the
enormous variety of life.
• They are ways in which
we study life (biology)
1.Diversity & Unity of Life
• Diversity: There’re lots of different
organisms in the world.
• Unity: All of these different organisms
have certain things in common
– All have the Characteristics of Life
– All have a genetic code
These relationships can be shown with a “tree
of life” model.
Three Domains of Classification
• 3 Categories of all living things
– 1. Eubacteria
– 2. Archae (2 forms of Bacteria)
– 3. Eukarya (all living things besides bacteria
belong to this group)
• Another way to categorize living things is
the “Kingdom” system
–6 Kingdoms
– Animalia
– Plantae
– Fungi
– Protista
– Monera
– Archaea
2. Interdependence
• Organisms & their environment interact
• Ecology studies this
• Ecosystems are communities of living
things and their environments
• Humans really interact with the
environment
3.Evolution of Life
• Changes can occur in a species over
generations
• New species can arise from drastic
changes in a population of a species.
• This explains the branches of the tree of
life
4. Genetics
• A species passes on traits from one
generation to the next.
5. Homeostasis
• All living things must have a way to
maintain stable internal conditions.
6. Cellular Structure & Function
• The cell is the basic unit of all life
• The cell is the smallest structure
considered living.
• All cells come from pre-existing cells.