Chapter
1.1 - How to Define Life
A. Living Things Are Organized
subatomic particles --> atoms --> molecules -->cells --> tissues --> organs --> organ systems --> organism --> population --> community --> ecosystem --> biosphere
Each level of organization has emergent properties; however, all new properties follow the laws of
physics and chemistry.
B.
Living Things Acquire Materials and Energy
1.
Maintaining organization and carrying on life requires an outside source
of energy (food, sunlight, chemicals)
2. Energy - capacity to do work; it takes work to maintain organization
of the cell and organism.
3. Metabolism - all chemical reactions that occur in a cell.
4. Ultimate source of energy for nearly all life on earth is the sun
5. Organisms must maintain homeostasis -or keep themselves stable
in temperature, moisture level,
acidity, etc. by physiology and behavior.
C. Living Things Respond
1.
Living things interact with the environment in order to find nutrients
or energy.
2. Responses to environment (stimulus) altogether constitute
the behavior of an organism.
D. Living Things Reproduce and Develop
1.
Reproduction is the ability of an organism to make another organism
like itself.
2. Bacteria, protozoans, and other unicellular organisms simply split
into two
3. Multicellular organisms often unite sperm and egg -> zygote
4. Genes are made of long molecules of DNA that specify how the organism
is organized.
E. Living Things Have Adaptations
1.
Adaptations - modifications that make an organism suited to its
way of life.
2. Natural selection is process by which species become
modified over time.
3. Evolution is descent with modification.
.1.2
How the Biosphere is Organized
A. Levels of Complexity
1. The biosphere is the zone of air, land, and water where life is found.
2. A population consists of all members of one species in a particular area.
3. A community consists of all of the local interacting populations.
4. An ecosystem includes all aspects of a living community and the physical environment, including
soils, atmosphere, etc.
5. Ecosystems are characterized by chemical cycling and energy flow.
6. Climate is the major determining factor of where ecosystems occur.
B.
The Human Population
1.
Humans modify ecosystems for our own purposes.
2. Some human activity threatens tropical rain forests and coral reefs.
3. Human beings depend on healthy working ecosystems for food, medicines,
and raw materials.
C. Biodiversity
1.
Biodiversity consists of the total number of species, their variable
genes, and their ecosystems.
2. Extinction is the death of a species or larger group; perhaps 400
species go extinct each day.
3. Preserving our biosphere helps ensure the survival of our species.
1.3 How Living Things Are Classified
A.
Taxonomy: the Discipline of Identifying and Classifying Organisms
1. Organisms are classified according to their evolutionary relationships.
2. As more is learned about organisms, the taxonomy changes.
B.
Categories of Classification
1. From larger categories to smaller: kingdom, phylum, class, order,
family, genus and species. (King Philip Came Over For Great Soup)
2. In the Kingdoms Plantae and Fungi, the category “phylum”
is replaced by “division.”
C.
Domains
1. Biochemical evidence breaks life into three domains: Bacteria, Archaea,
and Eukarya.
2. Eukarya have a membrane-bounded nucleus.
3. The prokaryotes are structurally simple but have complex metabolisms.
4. Archaea vary from regular bacteria; all Archaea live in water, cannot
tolerate oxygen, and have ability
to survive harsh temperatures, salts, and acids similar to what was
found on the primitive earth.
D.
Kingdoms
1. The Archaea and Bacteria are not yet characterized into kingdoms.
2. Eukarya contains four kingdoms: Protista, Fungi, Plantae, and Animalia.
