Lab 2: The Scientific
Method
Point of Today’s Lab
• In a real job, in real science, you will not have
a lab manual with a cookbook recipe of steps
for you follow
• Scientists get paid to figure things out….not do
experiments they already KNOW the answer
to
• A lot of being a scientist….is sitting in
confusion
Experimentation
• It’s how we learn important things
about the world
• Good experimentation: baby monkey
• Poor experimentation: kitten
• Observation: you
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Movies
You play the “Scientist”
everyday
• You stumble out of your room at 4
a.m. and turn on a lamp
• Nothing happens
• Now what? Curse the darkness?
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How has this been used?
• John Snow
– London Cholera Outbreak in 1854
– Thought it was spread by fog and mist
– Discovered it was from a contaminated water
pump
John Snow’s Map
The Road to DNA Discovery
• Erwin Chargaff
• Data displays that organisms have roughly
equal amounts of DNA base pairs
• Real structure later discovered by James
Watson and Francis Crick….Rosalyn Franklin?
Chargaff’s data
%A
%T
%G
%C
Mycobacterium
15.1
14.6
34.9
35.4
Yeast
31.3
32.9
18.7
17.1
Wheat
27.3
27.1
22.7
22.8
Sea Urchin
32.8
32.1
17.7
17.3
Marine Crab
47.3
47.3
2.7
2.7
Turtle
29.7
27.9
22
21.3
Rat
28.6
28.4
21.4
21.5
Human
30.9
29.4
19.9
19.8
Chargaff
• Maybe Chargaff didn’t discover the structure
of DNA….but he contributed a VERY
IMPORTANT OBSERVATION that lead to the
discovery. Sometimes we don’t always get a
conclusion. That’s okay. His observations many
scientists later
Unknown Liquids
• Mix samples and deduce something about
their relationship
• 3 mL in each tube
• You have indicators A & B, you also have
substances 1-6
– Addition of 5 drops should be enough for change
• KEEP TRACK OF WHAT YOU ADD TO WHAT
Pattern Master
• Bio 181L Go Folder Pattern Master
– Pattern Master for Fun- Select Demo
• Find a pattern relating to shapes, colors,
numbers, letters, etc.
• Put cards in correct order to make them all
“happy” or green
Rule Quest
Given 1-step clockwise*, it could be...
•Perimeter to top inner color
•Top inner color to lower left color
•Lower right color to lower left color
*NEIGHBOR definitions are clockwise, counterclockwise
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Homework
•
•
•
•
Quantum Mine (BONUS)
Logic of Disproof Assessor
Pattern Master (Individual)
Easy= 45 Points, Medium= 50, Hard= 55
– 50 for written portion (follow rubric)
• Written explanation of unknown liquids (Group)
– Rubric and example on lab calendar
Quantum Mine
• Bio 181L Go Folder Quantum Mine
– Don’t Log in- click “New Mine”
• Shoot light beams, find out where gems are
Rules of the Mine
or...
http://en.wikipedia.org/wiki/Black_Box_(game)
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