20-25 min introduction and make PVA slime
30-45 min assemble cell models
10-15 min create cell model keys
20 min discuss the metric system of measurement and use ratios to calculate the relative size of a person made of ziplock bag sized cells
Each student needs a copy of the Slimy Cell Models handout.
For enough PVA slime for a class of 30 students:
For cell walls, gather as many pint-sized strawberry baskets as you can – two baskets, one inverted over the other, readily enclose a filled ziplock bag, demonstrate the structural support provided by the cell wall, and illustrate the permeability of the cell wall.
For organelles, assemble a wide assortment of small, inexpensive items that students can select from. It is best to avoid food items like beans and candy since they will decompose and grow mold inside slime, creating a disgusting mess. An alternative is for students to bring objects from home for their models. Some items you may want to consider include: