The Science of Biology Ch 2

I. Science is Based on Inquiry and Observations Science = A way to answer questions about the natural world Starts with asking questions and making observations Uses the scientific method

II. The Scientific Method Observing and asking questions →make inference→ hypothesis → experiment→ analysis→ conclusion

Observation : – act of noticing things in nature Ex: many nonpoisonous snakes mimic the bright coloration of poisonous snakes

Question: based on observations Why do nonpoisonous snakes mimic poisonous ones?

Inference: – logical interpretation of the question Mimicry protects the nonpoisonous snakes

Hypothesis: – Educated guess or possible answer to a question. Based on observation. Has not been tested yet. If mimicry protects the snakes, then fewer colorful nonpoisonous snakes will be attacked than noncolorful nonpoisonous snakes

Experiment – Designed to test hypothesis – A controlled experiment has only one variable being tested or manipulated, the independent variable

Independent variable: the variable that you are changing Dependent variable is what is being measured or observed (the effect) all other variables in the experiment should be kept unchanged.

Some experiments have a positive control and a negative control – Positive control: – Negative control:

Analysis of data: record of observations Tables Graphs Written observations Drawings

Conclusions Summarizing the data collected Prove or disprove hypothesis If hypothesis is disproved did experiment fail?

Theory: A hypothesis tested MANY times and proven true. However it could eventually be proven false Law: a hypothesis that can NEVER be proven false