REVIEW UNIT 1 BIOLOGY

The Goals of Science To investigate and learn about the natural world. To develop explanations about the patterns and events in the natural world. Can you think of a pattern or event that scientists have investigated? To use those explanations to better understand and make predictions about the natural world. How can knowledge about that pattern or event help us better understand the world?

BIAS Prejudiced presentation of material or Consistent error in estimation of value

Types of bias Sampling bias Measurement bias Using an unrepresentative sample or group Using a small sample size Not using a random sample Measurement bias Inaccurate or inappropriate collecting techniques Allowing external variables to influence measurement

A good sample is… Randomly selected Large sample size Representative of a population

The Scientific Method Make an observation Ask a question Gather information Form a hypothesis Conduct an experiment Collect data Draw conclusions Retest Peer review

Types of observations Qualitative: a description Quantitative: numbers An observation made with your senses (sight, smell, touch, sound). Quantitative: numbers Observations that are actual measurements.

Hypothesis Must be testable and predict an outcome. Can be described as an educated guess Hypothesis should be stated using an “if…., then…” statement.

Conduct an experiment Only change 1 variable at a time Has a control treatment (nothing changed) and an experimental treatment (one thing changed).

Variables Independent variable: What you change Dependent variable: What you measure Controls: Everything else that stays the same!

Collect data Collect data from several trials. Examine data for trends. Create chart and graphs to organize and display data. Repeat experiments.

Draw Conclusions Accept or reject your hypothesis based on your data.

Peer review Evaluation by other scientists in the same field Publishing the experiment & results

A THEORY A hypothesis that is generally excepted as true due to the amount of evidence supporting it.

Unit Conversions Changing a measurement from one unit to another. For example: 1 foot = 12 inches Likewise: 1 foot = 30.5 cm

Metric system Length: Meters Weight: Grams Volume: Liters

Countries That Do Not Use the Metric System http://twistedsifter.files.wordpress.com/2013/08/ map-of-countires-that-use-metric-system-vs- imperial.jpg