This is adapted from sample NGSS assessments released at www.ngss.org. In this lesson Task 1: NATURAL SELECTION and the FREQUENCY of TRAITS in
BACTERIA POPULATION is broken down into a student worksheet with teacher answer key. Students analyze data by looking at frequency of traits in bacteria in petri dishes. They graph data and analyze their graphs looking for patterns. Students construct an explanationfor why the measured frequencies either match or do not match their prediction. They use their graphed data to support their claim.