What is a 3D object that I can use to represent a cell membrane?

For my Biology class, my teacher gave us very vague instructions to bring a 3D object into class to represent a cell membrane tomorrow, and I would ask her but by the time she got my e-mail, it would be too late for me to turn it in. I am very confused, please help!
Thanks in advance for your help!
-Emily
4 answers 4