BIOLOGY: Chapter 1

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BIOLOGY Chapter 1

• The Science of Biology

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1.1 The Science of Biology

• Science is basically two things
• A body of knowledge an accumulation of things we
  have learned about the universe
• A process an organized way of gathering and
  analyzing evidence

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Goals of science

• The goal of science is to provide explanations
  for events in the natural world
• Learning about science involves understanding
  what we know, but also means understanding what
  we DONT know
• Uncertainty is part of the scientific process and
  is limited by our technology and methods

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The Scientific Method

• An organized process used to answer a question
• Start with a testable hypothesis
• Repeatable experiments
• Conclusion must be supported by the data
  scientists sometimes overreach their experiments
  and jump to conclusions

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The Scientific Method

• Background research to understand the state of
  knowledge of the subject before you begin What
  is already known about the topic? What types of
  methodology have been used in similar
  experiments? Thorough background research is
  what makes the educated guess educated ?

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The Scientific Method

• Form a testable hypothesis based on your
  background research
• Design a repeatable experiment using the
  appropriate controls and variables (only
  manipulate one variable at a time!)
• Conduct the experiment and record data
• multiple trials
• samples size must be appropriatebigger is
  better!

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The Scientific Method

• 5. Analyze the data statistical analysis and
  graphing (how different is different?!)
• 6. Form a conclusion use your data analysis to
  determine if your hypothesis was supported
• 7. Report your results scientific research
  journals, conferences, etc

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Example of a scientific hypothesis

• Null hypothesis (Ho) The male and female
  students have the same IQ
• Alternative hypothesis (Ha) The male and female
  students have significantly different IQ scores
• Must use statistical analysis to show
  significance

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Example of a scientific hypothesis

• Control (population) Avg IQ score 100
• Male test group (n10) Avg IQ score 101
• Female test group (n10) Avg IQ score 102
• Are these two results truly different? Depends on
  the sample size and the range must use
  statistics to determine, but probably not!

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Controls and variables

• Control group exposed to the same conditions as
  the experimental group with the exception of the
  experimental variable the control group is the
  standard against which the experimental groups
  are compared
• Independent variable the condition that is
  tested (ie the thing you change in the
  experiment)
• Dependent variable the condition that results
  from changing the independent variable (ie what
  is observed or measured)

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DRY MIX How to graph results

• D dependent variable
• R also called the responding variable
• Y graphed on the Y axis
• M manipulated variable (what you change)
• I also called the independent variable
• X graphed on the X axis

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Writing experimental procedures

• Must be clearly written so that anyone can follow
  your instructions
• Numerical order, like writing a recipe
• Use sizes, amounts, units of measure
• Full sentences with punctuation!
• Include safety procedures, set up and disposal
  procedures
• Make sure to include number of trials, sample
  sizes, etc

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Results/discussion

• Results should be given in both graphs/charts and
  written form
• Extensive discussion attempts to make sense of
  what you found
• What does the data mean?
• What kinds of things made sense or not?
• Problems or other questions that arose?

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Conclusions

• Was your hypothesis supported?
• Do not overreach the limits of your study
• The case of the biting dogs

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Recommendations/Future studies

• Addresses possible solutions to problems you
  encountered
• Things you would like to do differently or repeat
  in a different way
• Offshootswhat other questions did your
  research raise? This is how most real research is
  generated!
• Some researchers work their entire careers on the
  basis of one original question ?

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Publication/peer review process

• Peer reviewed literature is often very specific
  to certain disciplines (ie scientific journals)
• Process involves sending drafts of manuscripts to
  experts in the field who review it anonymously
  and make recommendations
• Edits and revisions are the norm, sometimes very
  extensive
• Often takes up to a year or more
• Helps to keep science honest and as correct as
  possible

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1.2 Science in context

• Attitudes of a good scientist
• Curiosity
• Skepticism
• Open-mindedness
• Creativity

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1.2 Science in context

• Theory a well-tested explanation that unifies a
  broad range of observations and hypotheses and
  enables scientists to make accurate predictions
  about new situations
• Theories are based on much EVIDENCE and supported
  by DATA

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Theories vs. laws

• Theories do not become laws!
• Laws (such as ideal gas laws or Newtons laws)
  are concise and specific descriptions of how some
  aspect of the natural world is expected to behave
  in certain situations.
• Theories are more dynamic and complex. They
  encompass a greater number of ideas and
  hypotheses than laws and are constantly
  fine-tuned through the process of science.

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Bias

• Scientists must make every effort to avoid bias
  (bias is not scientific!)
• Bias does creep into science through funding and
  political issues, but should be seen and
  confronted
• The case of the disappearing whales of Prince
  William Sound

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Exxon Valdez spillPrince William Sound AK1989
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1.3 Studying Life

• How do biologists determine if something is
  living or nonliving? (biotic or abiotic)
• They must meet certain criteria
• Some things (VIRUSES!) meet some but not all of
  the criteriagrey areas exist

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Characteristics of Living Things

• Based on a universal genetic code (DNA)
• Grow and develop
• Respond to their environment (stimulus
  response)
• Made up of cells
• Reproduce (asexually or sexually)
• Maintain a stable internal environment
  (homeostasis)
• Obtain and use energy and materials (metabolism)
• Taken as a group, living things evolve.

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Three Domains of Life
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6 kingdoms of organisms
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Biotic vs. Abiotic