Download Scientific Method

APES DO NOW
• Turn in Tragedy of the Commons
• List the main environmental problems facing
the world today.
• List the CAUSES of those problems.
Scientific Method
Steps
Independent vs. Dependent Variables
Control vs. Constant
Scientific Method
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4.
Question or Problem?
Background Research
Hypothesize
Create Procedure +
Experiment
5. Analyze Data + Results
6. Conclusion
What is a variable?
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Effects of vitamin C on life span
Effect of fertilizer on plant growth
Effect of drug dosage on symptom severity
Effect of temperature on dissolved oxygen
Types of Variables
Types of V ariables
Definition
Independent variable
Manipulated variable, what is being changed within the
experiment
Dependent variable
Responding or measured variable, what is being measured or
observed
Baseline for comparison of results
Control
Conditions that are not changing but remain consistent throughout
Constants
Your Turn!
Practice Identifying Variables
• Students of different ages were given the same
jigsaw puzzle to put together. They were timed
to see how long it took to finish the puzzle.
time
• Dependent variable:
ages
• Independent variable:
• Constants: Same puzzle
Inductive vs. Deductive Reasoning*
Inductive = from specific to the general, starts from
observation + evidence and leads to conclusion
• Example: that every time you eat a hot dog with chili and onions, you get a stomachache.
Using inductive reasoning, you could logically conclude that the chili dogs cause indigestion, and that
you should probably stop eating them.
Deductive = moves from a conclusion to the
evidence for that conclusion
• Example: All men are mortal. Socrates is a man.
Therefore, Socrates is mortal.
Chemistry Review
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Matter
Elements
Atoms  protons, neutrons, electrons
Compounds
Cations and Anions
Mixtures: homogeneous (solutions = solute +
solvent) and heterogeneous
• Atomic number, Mass number
• Isotopes
Energy Types
• POTENTIAL (stored) vs. KINETIC (motion)
• Law of Conservation of Matter
Energy Loops
Positive Feedback Loop
• End result is often
explosive or amplifying
• “cummulative
causation”
• EX: contractions, blood
clotting, fission
Negative Feedback Loop
• End result is often
equilibrium
• “homeostasis”
• EX: thermostat
Laws of Thermodynamics
• 1st Law: energy cannot be created nor
destroyed, it only changes forms
– Deals with quantity of energy
• 2nd Law: “Entropy Rules”, amount of useable
energy decreases as energy changes forms,
10% gets transferred, 90% dissipated
– Deals with quality of energy (high vs. low)
Energy Transfers
Conduction –
through direct
contact
Convection –
by molecular
movement
Radiation – by
wave energy
Biology Review
A human body contains trillions
of cells, each with an identical
set of genes.
Each human cell (except for red
blood cells) contains a nucleus.
Each cell nucleus has an
identical set of chromosomes,
which are found in pairs.
A specific pair of chromosomes
contains one chromosome from
each parent.
Each chromosome contains a
long DNA molecule in the form
of a coiled double helix.
Genes are segments of
DNA on chromosomes that
contain instructions to make
proteins—the building blocks of life.
The Electromagnetic Spectrum
Fig. 2-11, p. 45
Systems Have
Inputs, Flows, and Outputs
• System
– Set of components that interact in a regular way
– Human body, earth, the economy
• Inputs from the environment
• Flows, throughputs of matter and energy
• Outputs to the environment