Criteria for Life

Sixth graders conducted an investigation to see if samples found in petri dishes had characteristics of life.  The criteria they used is that all living things are made up of cells, exchange gases, use energy, reproduce, and respond to their environment.  The samples included sand, sand and alka-seltzer, and sand and yeast.  After the investigation, students decided that the sand and yeast was the only sample that actually met all of the criteria after hot water had been added to the samples.