A great variety of kinds of living things can be sorted into groups in many ways using various features to decide which things belong to which group. Features used for grouping depend on the purpose of the grouping. Other likenesses, such as people's table manners or carpentry skills, are learned. For offspring to resemble their parents, there must be a reliable way to transfer information from one generation to the next.
Microscopes make it possible to see that living things are made mostly of cells.
Some organisms are made of a collection of similar cells that benefit from cooperating. Some organisms' cells vary greatly in appearance and perform very different roles in the organism. Students explore both terrestrial and aquatic environments. In the activities, students determine the environmental preferences, optimal conditions, and tolerances of several organisms, by examining the specific needs of that organism. At the conclusion of each set of investigations, students communicate their findings in the form of recommendations for optimal environmental conditions for each organism.