Download MS Word File

5/22/12
Hierarchy of Life
Or
Big Themes in Biology
Hierarchy of Life: (multicellular organisms only)
Cell is basic unit of life
Atoms and molecules are not living
Tissue=collection of similar cell types
Organ=collection of tissues that work together
Organ system=Organs and auxiliary tissue that serve a common role
Organism
Even further could consider communities, ecosystems, etc.
Emergent properties=the whole is greater than the sum of its parts.
Cooperative effort among units = coordination.
Diversity of Life-variability of living organisms
Diversity on grand and small scales
Classification of organisms-hot issue right now
5 Kingdoms: Prokaryotae, Protoctista, Fungi, Plantae and Animalia
Dispute over superkingdoms or Domains
2 superkingdoms: Prokarya and Eukarya
3 Domains
Archaea=Archaebacteria
Bacteria=Eubacteria
Eukarya=Eukaryotes
Evolution through natural selection=framework in which biology is studied
Mutations that are beneficial become more common in later generations
Changes occur resulting in organisms are well-suited for environment
Energy flow through systems-Ecology
Sunlight-plants-herbivores-carnivores-heat
Complex relationships and can be delicate
Scientific method
Hypothesis driven research
Hypothesis is a prediction based on previous observations
Several hypotheses may be possible for one system
Test hypotheses by experimentation or observation
Can eliminate incorrect hypotheses but never "Prove" a hypothesis
Supporting data
Hypotheses that stand up under many experiments are "Laws"
Open for disagreement
Viruses living?
There is some observation or objective driven research, but it could
eventually be used to formulate hypotheses.
Model systems-used to gain information about another system
Most often used to gain information on humans
Yeast, flies, worms, fish, mammals-many systems exist
Often confusing to general public
Why bigger rats or cancer-free flies?