1. Warm Up #1
The active ingredients in many pesticides are chemical compounds that kill organisms such as insects, molds, and weeds. They can also have unintended consequences…
Design a laboratory experiment to determine whether or not a new pesticide (product X) is toxic to minnows, a type of small fish.
Include the hypothesis, how you would test it, a control and an independent variable

2. Scientific Method

3. Scientific Method Step 1: OBSERVATIONS Things that you notice
Example: Many pesticides being used are killing organisms other than the intended pests (such as minnows)

4. Scientific Method Step 2: HYPOTHESIS
Educated guess based on observations
If/Then statement OR a Declarative statement
Example: If Product X is added to water, then it will be toxic to fish OR
Product X is toxic to fish when added to water.

5. Scientific Method 2 Major Groups
CONTROL GROUP
EXPERIMENTAL GROUP
Remains constant, serves as baseline
Tank WITHOUT product X
Others controls:
Amount of water
Amount of fish in each tank
Temp/light conditions
Group being tested
Concentration of Product X in tank
INDEPENDENT VARIABLE – something YOU are manipulating/changing
Mortality rate of minnows
DEPENDENT VARIABLE – EFFECTS of independent variable manipulation

6. Scientific Method To Have GOOD Results:
Multiple Trails (ensures PRECISION – same results each time)
Large Population Size (ensures ACCURACY – no skewed data)
Multiple Experimental Groups (varying concentration levels of Product X)

7. Multiple Experimental Groups
TANK 1:
NO PRODUCT X
TANK 1:
MEDIUM PRODUCT X CONCENTRATION
TANK 1:
HIGH PRODUCT X CONCENTRATION
TANK 1:
LOW PRODUCT X CONCENTRATION

8. Quick Quiz #1
How does an independent variable differ from a dependent variable?
Describe experimental results that would lead you to reject your hypothesis in part (a). (Be specific.)