Exploring Life
Properties of Life
 Order
o Organisms are highly ordered
o Other characteristics of life emerge from this order
 Reproduction
o Organisms reproduce their own kind
o Life comes only from life
 Growth and Development
o Heritable programs in the form of DNA direct the pattern of growth and development
 Energy Utilization
o Organisms take in and transform energy to do work
 Response to Environment
o Organisms respond to stimuli from environment
 Homeostasis
o Organisms regulate their internal environment to maintain a steady-state, even in the face of a fluctuating
external environment
 Evolutionary Adaption
o Life evolves in response to interactions between organisms and their environment
Levels of Biological Organization
1. Biosphere
o All of the environments on earth that
contain life
2. Ecosystems
o All of the living and nonliving things in a
particular area
3. Communities
o All of the living things in an area
4. Population
o All of the individuals of a species living
in a certain area
5. Organisms
o Individual living things
6. Organs and Organ Systems
o A body part made up of tissues
o A group of organs working together for a
specific purpose
7. Tissues
o Group of similar cells
8. Cells
o A fundamental unit of structure and
function
9. Organelles
o Various components that make up cells
10. Molecules
o Chemical structures consisting of atoms
Major Processes in Ecosystems
 Cycling of Nutrients
o Minerals (inorganic materials) acquired by organisms from a source are returned to the source
 Carbon Cycle
 Nitrogen Cycle
 Flow of Energy
o Flow of energy from sunlight to produces and consumers (not recycled)
Biological Systems
 Emergent properties
o Properties that emerge in the levels of biological organization as you go up that are not apparent in lower
levels
o Ex) Chlorophyll and other molecules put together will not produce photosynthesis – only chloroplasts
(higher level) can photosynthesize
 Reductionism
o Process of reducing complex systems to simpler components so that it is easier to study the system
 Positive Feedback
o The presence of the product increases the production of the product
o Ex) Breast feeding (more sucking results in more milk and more milk results in more sucking)
 Negative Feedback
o The presence of the product decreases the production of the product
o Ex) Sweating (body is hot so it sweats; body temp lowers so sweating stops)
Taxonomy
 Naming and classifying of species into groups
 Most inclusive → least inclusive (Dumb King Phillip Came Over From Greater Spain)
o Domain
o Kingdom
o Phylum
o Class
o Order
o Family
o Genus
o Species
Experimental Vocabulary
 Discovery Science
o Describes natural structures and processes of live from observations and analysis of data
o Based off of inductive reasoning
 Generalizations formed from data
 Hypothesis-based Science
o Involves the proposing and testing of hypotheses
o Based off of deductive reasoning
 Reasoning that goes from general to specific and can be tested
 Variable
o Any condition that may cause a change in the system being studied
 Controlled experiment
o Only one variable is changed to ensure that the effect of only that one variable is measured
 Independent variable
o Changed by the experimenter in the design of the experiment
 Dependent variable
o What changes as a result of the change in the independent variable
 Controlled variable
o Variables that are kept constant because they may change the outcome of the experiment
 Research question
o States the independent and dependent variables as well as the purpose of the experiment
 Control group
o A set of organisms or samples that do not receive the treatment (independent variable) being tested
o (used to cancel the effect of non-experimental variables)
Biological Themes
Biological Theme
Emergent Properties
Cells (Cell Theory)
Heritable Information
Structure and Function
Interaction with the Environment
Energy and Life
Regulation
Explanation of Theme
Characteristics immerge as you go up
the levels of biological organization
that were not present in lower levels.
all living things are made of cells; cells
are the basic unit of structure and
function in living things; cells are
produced by other living cells
All forms of life contain basically the
same genetic code. The genome is the
entire library of genetic instructions
that an organism inherits.
A structure hints at the function of a
biological structure and the function
can explain the biological structure.
Specific structure for a specific
function.
Organisms interact with living and
nonliving factors in their
environments.
Life requires the uptake and release of
energy
A product regulates a mechanism
Unity and Diversity
Life has many characteristics in
common at the lower levels; however,
it is extremely diverse because it has
also branched out of its commonality.
Evolution
Life branches in multiple directions
from common ancestors. Evolution is
the changing of life.
Scientific Inquiry
Science, Technology and Society
Theories are developed in science but
nothing can ever be “proved”; only
supported.
Technology results from scientific
discovery and scientific discovery
results from better technology.
(Positive feedback… anyone?
anyone?)
Elaboration (Examples)
Chlorophyll + parts do not make
photosynthesis occur. Only
Chloroplasts can do that and they are a
higher level of organization
Prokaryote vs. Eukaryote
DNA, proteins, chromosomes
Bird’s Wings:
Structure = honeycombed bones
Function = flight
Nutrient Cycles (CO2 & N)
Flow of Energy (Sun → producer →
consumer)
Flow of Energy (Sun → producer →
consumer)
Energy Conversion (Solar →
Chemical → Potential/Kinetic, etc.)
Positive Feedback (product increases
process)
Negative Feedback (product decreases
process)
DNA connects all life to one another;
some cellular structures are similar
among organisms (common ancestry)
but after those levels, life becomes
extremely diverse (natural selection).
Mammals are all connected because
their common ancestor was the first to
have hair and milk but mammals have
branched out since.
Discovery vs. Hypothesis-based
Science
Experiments
Technology and science push each
other forward but each can have
devastating consequences
(deforestation, ozone holes, gene
manipulation)