Im going to have to go with C. they pass through channels in the cell membrane
Molecular biologists are interested in things like the level of gene expression (how much protein or RNA is present at any given time), which molecules are directly touching each other inside the cell, etc. ... Cell biology techniques, on the other hand, want to know what's going on inside intact cells.
( Try to see which one sounds best after reading this)
Most of the ways to stop invasive animal species from entering the Great Lakes ecosystem is starting with people themselves. try not to plant anything that would be invasive to the echo system and also try helping out by cleaning out the Great Lakes by picking up litter and so forth