Chapter 1 (What is Life?)
How do I know that you are living?
Life is defined in terms of qualities that the living
Life is organized -in a sequence of increasing complexity (structures within structures) -the basic unit of life is the cell -levels of biological organization extend from within the individual organism to the biosphere
Life requires energy -the natural tendency of matter is towards disorder (i.e., entropy or randomness) -living systems acquire and use energy to maintain their highly organized state -metabolism: the biochemical reactions that acquire and use energy
Living things must maintain an internal constancy -living things must maintain their separation from the non-living world -for metabolic processes to function normally, living things need to keep themselves stable in temperature, moisture level, chemistry, etc. -homeostasis: the ability to maintain chemical constancy (i.e., to stay the same)
Living things react to environmental change (an individual reacts to its environment) -behavior - move towards or away from stimuli -change in metabolism -change in development
Living things grow, develop, and reproduce -vital if a population of organisms is to survive more than one generation -"Instructions" for growth and development are encoded in genes
Living things adapt (evolutionary change over many generations) -an inherited characteristic or behavior that enables an organism to live and successfully reproduce in a given environment -life can adapt to a wide range of environmental conditions -these adaptations/modifications accumulate in a population of organisms when individuals with these traits are more likely to reproduce than others
Chapter 2 (Thinking Scientifically About Life)
Chapter 44 (Environmental Concerns)
Web link to Life, third ed.
Question 3, Page 15.
Questions 1-4, 7, Page 30.
Question 5, Page 16.
Some useful (and not so useful) WWW sites:
Chapter Related Web Sites from Life
New York Times
Smithsonian Institution National Museum of Natural History
Virtual Frog Dissection Kit
Popular Science Magazine
Tasty Insect Recipes
The study of the living world is complex and
messy because of the infinite number of interactions
that must be considered:
Knowing the facts of biology without an understanding
of these relationships is insufficient to understand
the biological world.
How do I know that you are living?
Life is defined in terms of qualities that the
living uniquely share:
All living things share the same basic characteristics outlined above.
This unity suggests that all living things are descendant from a common
ancestor. Living things are diverse because of adaptation to various ways of life.
Evolution:Theories and History
The scientific method of investigation involves making a series of inquiries
by observing, questioning, reasoning, predicting, testing, interpreting,
and concluding. However, because these inquiries often spawn new ideas and
raise new questions, the scientific method is a cycle of inquiry, with the search
for knowledge never ending.
Note: These links should be used in order to understand
how the application of the scientific method refuted
the theory of spontaneous generation.
We may never truly know that reality.
Each of us has our own view of the natural world that is viewed through the lens of our previous experience and knowledge.
Science strives to be objective, and is founded in the belief that events can be explained fully by natural causes. Conversely, explanations based in supernatural causes are not considered to be scientific.
Scientific explanations of phenomena observed in the natural world are called hypotheses (singular: hypothesis).
Scientific hypotheses must be testable and falsifiable. If the hypothesis is incorrect it can be tested by experimentation and/or observation and proved to be false.
Experimentation and observations can increase our confidence that a hypothesis is a correct explanation of a phenomenon, but can never absolutely prove a hypothesis to be true.
Once a hypothesis has been supported by many experiments and/or observations it is considered by the community of scientists to be a theory. (Note that this is very different from the common use of the word, meaning an opinion or a guess.)
The conclusions of science are subject to change. New studies, which might utilize new techniques and equipment, may reveal that previously accepted theories need to be modified or changed entirely.
Great science is replaced by greater science.