How does the filtration membrane prevent certain substances from entering the filtrate?

In which of the following ways is the function of the surface of a microsphere similar to the function of an actual cell membrane? a.both make it possible for the conditions in the interior to be different from the conditions outside. b.both provide a barrier that keeps water from flowing across it so the interior remains dry. c.both separate the rna that forms in the interior from any rna that might form in the environment. d.both can actively move molecules into the interior or out into the surrounding environment.

An atom of nitrogen had seven protons in its nucleus. how many electrons does it have

Which situation is an example of not doing work? lifting a couch throwing a baseball running up stairs carrying a box