Chapter 1 (What is Life?)
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.

Answers to many of these questions can be found on the "Answers to End-of-Chapter Questions" page at the text website.
Feedback can also be obtained by posting possible answers in the appropriate folders of Web Crossing. More information to follow.

• Read chapter 44 in Lewis.
  
• Select a topic addressed in that chapter that interests you.
  
• Find and read an article in a newspaper, a news magazine, a science magazine or journal, or a WWW site.
  
• Bring a copy of the article to discussion or lab class and be prepared to discuss it.
  

1. Define the term "Biology."

2. List and understand the combination of characteristics that distinguishes the living from the nonliving.

3. Outline and describe the logic behind the basic steps of the scientific method.

4. Explain what is meant by the phrase "science as a way of knowing."

.

The study of the living world is complex and messy because of the infinite number of interactions that must be considered:

• within a cell
• among cells in an organ
• among the organ systems in an organism
• between organisms and the abiotic environment
• among individuals in a population
• between species

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:

• 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

Seabathers Eruption (From http://www.fau.edu/safe/sea-lice.html)

SEA LICE

The Process:

The scientific method of investigation involves making a series of inquiries by observing, questioning, reasoning, predicting, testing, interpreting, and concluding. However, because these inquiries spawn new ideas and raise new questions, the scientific method is a cycle of inquiry, not a simple linear process of investigation.

• Make observations, ask questions, and consult prior knowledge

• After synthesizing this information, formulate a hypothesis - a tentative EXPLANATION of the observed facts (i.e., this is how I think the natural world works)

• Design an experiment or observation to test the hypothesis

• Make a prediction based on the hypothesis. The prediction is often phrased in conjunction with the hypothesis as an "If........then....." statement.

  IF - state your hypothesis- THEN - state your prediction

  • controlled experiments can be done in a laboratory or the "field"
    
  • experiments can be purely observational
    
  • experiments can be conducted using computer models

• Collect and interpret data

• Repeat the steps above based upon what is learned.

• Draw conclusions
  -these conclusions either refute or support the hypothesis

• These conclusions and further observations spawn other questions, hypotheses, and experiments

• A scientist believes that the natural world is a physical reality, but that we can only construct a conceptual view of that reality based upon observation and experimentation.

• 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.

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