I got this question marked wrong on a paper. Unfortunately, my prof didn't explain.

_________________ subtances can pass through the plasma membrane.

I put "nonpolar". What is wrong with this and does anyone know the correct solution/answer? Thanks all.

http://www.recreation.ucsb.edu/ess/ess40/downloads/chap3.pdf

http://scientia.org/cadonline/biology/eukaryotic/plasmembrane.ASP

Nonpolar is wrong. Polar water molecules pass through easily.

There are three ways substances can pass true. I have no clue to the answer if one word is desired. "Transported" will work, however it is an incompleted answer. Visit the prof.