Biology Lab

Scientific Method Step 1

identify problem via observation

Scientific Method Step 2

hypothesis

Scientific Method Step 4

collect unbiased data via experiments

Scientific Method Step 5

analyze

Scientific Method Step 5

repeat steps 2-4 until conclusion

Is there “proof” in science

There is no proof in science bc it is possible to disprove anything

What do theories become if they are disproven?

Laws

Can laws be disproven?

Yes

Variables

can change during the process, only change one variable at a time

Dependent Variable

results depend on what changes in variable

measurable effect

independent variable

thing that you will change

Positive

expecting a particular result and take measured steps to validate the hypothesis.

negative

omit some aspect

What percentage of women died shortly after giving birth in the Semmeleweis Case Study?

20%

Obsetrical

Women giving child birth

How much greater was women dying after child birth in the male led ward?

4 to 5 times greater

Autopsy

examining dead body for cause

What was Semmelweis’ solution to childbed fever?

Washing hands with chlorinated lime water

What was the conclusion of Semmelweis’ case study?

Something was contaminating and being transferred from the autopsy

How did Semmelweis die?

Puerperal sepsis

Quantitive Measures

Equiptment (ruler or stopwatch for example)

Qualitative Measures

Describe a characterisitc (ex: gender, texture, taste, presence, absence)

Dynamic Range

Ratio between the smallest and largest possible values it can measure

How can you improve the reliability of a measurement

Replicate it

Mean

Best guess at the true measurement (i.e. accuracy)

Standard deviation

precision

Accuracy

,

Precision

How repeatable the measurement is