Honors Biology Chapter 2
The Science of Biology
Concept 2.1: Discovery Science Emphasizes Inquiry
and Observation
• I. Science as Inquiry
•
A. Science = “to know”, to answer ?’s
about the natural world
•
1. 2 main forms of science
investigation:
•
a. Discovery Science =
Describes Nature
•
b. Hypothesis Based Science
= Explains Nature
• B. In Inquiry based Biology – ask
thoughtful ?’s, and then search for
answers
• C. Takes talent to know “what to ask!”
II. Observations and Data
• A. Observation = use of senses to gather
and record info
• B. Data = recorded observations
• C. Scientific instruments – increase range
of possible observations (telescopes,
microscopes)
D. Two types of Data:
• 1. Quantitative Data = measurements,
amounts (involves numbers)
•
a. Ex. Height, length, temperature,
how many, degrees, etc.
• 2. Qualitative Data = descriptions,
sensory impressions
•
a. Ex. Color, smell, taste, sound,
behavioral observations
• Data should be: clearly organized (tables,
charts, graphs), consistently recorded,
reliable
III. What is Discovery Science?
• A. It is Descriptive Science!
•
1.Ex. Jane Goodall and Chimpanzees,
collecting and id’ing orgs in river,
describing cells seen under a microscope,
etc.
•
2. Can occur entirely by accident, too!
•
- Ex. Alexander Fleming’s
discover of penicillin (Read p. 26)
• B. Inference = logical conclusion based on
observations
•
1. Help refine general ?’s into specific ?’s to
explore further
•
a. Ex. Something in the mold
prevented the bacterial growth in Fleming’s
culture
•
2. Good inference – does not stretch too far
beyond the data
•
3. Ex. Inference exercise: photo p. 27
• C. Generalization = broad conclusion
based on many specific observation put
together
•
1. Ex. All living things made of cells –
generalized from observing cells in all type
of samples from many types of orgs.
•
2. Can also be made from quantitative
data (graph of boy vs. girl height p. 28)
• D. Discovery science often leads to
Hypothesis based Science! – to test if
generalizations and inferences are true,
and to determine causes of some
discoveries!
Concept 2.2: Hypothesis Based Science is a Search
for Explanations
• I. Methods of Hypothesis Based Science
•
A. Scientific Method: a plan of attack,
not always completely followed! (Read
p.30)
•
1. Diagram – p. 30: Observation,
Question, Hypothesis, Prediction, Test
(Replicate, Report)
•
a. “PHEAC, R2”
• B. Hypothesis = suggested answer to a
well-defined scientific ? (Or: an
explanation on trial)
•
1. Should allow you to make
predictions in an
“If…………then……..”format
2. Ex. Dead flashlight p. 31
• C. Case Study of Hypothesis Based Science –
Read p. 32-35
•
1. Controlled Experiment = tests the effects
of a single variable only
•
a. Variable = condition that can vary
within an experiment
•
b. Eliminating unwanted variables done
by: dividing test subjects into 2 groups
•
1.) Experimental group
•
2.) Control group
•
3.) Constant = all variables that
are kept the same for all groups in the
experiment
• 2. Organizing Data and Interpreting
Results
•
a. Quantitative Data – more easily
interpreted in chart and/or graph form
•
1.) Graphs – useful in seeing
trends at a glance
•
2.) Ex. Graph p. 35
Concept 2.3: Understanding Science will help You
Evaluate many Issues
• I. Evidence = (in science) collected body
of data from observations and experiments
•
A. Must be repeated multiple times
with similar results for scientists to accept
it as valid.
•
B. Useful to evaluate everything from
ads for food supplements, to “miracle”
cures
II. What makes a hypothesis
“scientific”?
A. Must be testable, otherwise worthless!
B. Can either be supported or
contradicted by an experiment (Is it
“falsifiable”)
C. Scientific hypotheses may be rejected
later, esp. with new equipment advances.
1. Ex. Fungi once thought closely
related to plants, but DNA technology
refutes that idea now.
III. Limitations of Science
• A. Restricted to natural causes for natural
phenomena
•
1. Many things cannot be “tested”
scientifically
•
a. Ex. Cannot prove/disprove with
science that rainbows, storms, etc. caused
by unobservable or supernatural forces
• 2. Not everything you “know” is based on
science, either
•
a. Ex. You “know” what type of music
you like, what your favorite color is, etc.
•
b. Ex. You “know” right from wrong –
ethical value
IV. Theories
• A. Theory = well-tested explanation that makes
sense of a great variety of scientific observations
•
(ties together many different sets of
observations and data)
•
1. Can result in many different hypotheses
that can be tested
•
a. Ex. Theory of Natural Selection –
explains many different adaptations of orgs. to
envir.
•
2. Can be modified or replaced with new
evidence
V. Models
• A. Model = physical, mental or
mathematical representation of how
people understand a process or idea
– 1. Ex. Drawing, graph, 3-D object, computer
program, math equation, or verbal description
or analogy of how process works
– 2. Judge value of models on: does it
explain, can it help predict, does it match new
observations?
• - 3. Poor models don’t last
VI. Communication in Science
• A. Scientists rarely work alone (unlike
movie sci.)
• B. Communicate by: journal articles,
giving talks at meetings, internet
communication, etc.
C. Competition/Cooperation driving forces
•
1. Ex. Race to map the human
genome (not in text)
VII. Science, Technology and
Society
• A. Technology’s Goal = to apply science
to a specific purpose
•
1. Scientists (biologists, ex.) make
“discoveries”
•
2. Technologists (engineers, ex.)
create “inventions”
Examples of Technology
• 3. Ex. Watson and Crick – discovered structure
of DNA molecule
•
Medical Technologists – working to cure
diseases with recombinant DNA technology
• 4. *Technology often driven by current human
needs and values.
– Ex. Should people be tested for genes for diseases?
Should we perform stem cell research to cure
disease?
• Notice: not “can it be done” but, “should” it be
done?