In this activity students work as a team to determine the effect salt has on plant germination. They then use their lab data to create a report on how the increasing salt concentrations affected the germination of the seeds and at what salt concentration no seeds will germinate. Students will discover that salt buildup is an existing or potential hazard on almost all of the 42 million acres of irrigated ... Full description.

In this lesson, each student is given a block of wood and a screw (or nail), and is asked to put the screw into the block, without any tool (like a screwdriver or hammer). Their efforts, with varying success, lead to a discussion of contrivances, using various items and strategies as make-do (contrived) tools for which they were not intended, and an exploration of many examples of contrivances or ... Full description.

In this lesson, students will learn that geological time can be measured in several different ways, providing independent lines of evidence for measuring deep time and sequencing geological and biological events of the past. Students explore different methods of measuring geological time, comparing the time dimensions, mechanisms, and materials used for each. Full description.

In this lesson, students are given a variety of materials and are asked to design a heat loss experiment that will result in a reasonable explanation of why whales do not have legs. Students will learn that natural selection favors a body design that is energy efficient. Full description.

This lesson teaches students that traits are usually favored by natural selection only when they result in more reproductively successful offspring. Students go out onto the school lawn and play the role of birds, picking up toothpick stick worms which have been previously scattered in equal numbers of green-stained and unstained. Birds are chased away before the worm population drops too low. Back ... Full description.