This is a great lab for students to conduct in order to see how the cell membrane of an egg works. Over the period of a week students place the egg into three different liquids in order to see if the cell membrane will allow the liquid into the egg. Students record the mass and circumference of their egg in order to gather evidence for their final conclusion. At the end of the lab, students have to use the NGSS format of claim-evidence-reasoning in order to support their answer. I have modified this lab by doing a demonstration with only one egg per hour instead of each student having an egg or you could incorporate more math measurements and have students graph the data as well.