She explains that they will be doing an experiment to show how important the waxy covering is. Teacher shows the groups that they will be given 2 sponges, one covered on all sides but one with Vaseline. They will be placing the sponges in containers of water. They will then take the sponges out of the water and leave them a while to dry. Later they will see if the sponge covered in Vaseline retained more water.
Students perform the experiment and then leave the sponges out to dry.
Teacher explains that they will be reading about a special type of cactus, the saguaro cactus. It is found only in the Sonoran Desert of southern Arizona and northern Mexico. These cacti are prized in this region. She asks comprehension questions. Teacher asks the students what they expect to find when they return to their experiments.