Answer:
My guess would be H₂O/ water, since osmosis is a form of passive transport and I can't see the model the question references. Gases like O₂/ oxygen, CO₂/ carbon dioxide, and simple sugars like glucose can also pass through a cell membrane with passive transport though.
Answer:
Small uncharged polar molecules, such as H2O, also can diffuse through membranes, but larger uncharged polar molecules, such as glucose, cannot. Charged molecules, such as ions, are unable to diffuse through a phospholipid bilayer regardless of size; even H+ ions cannot cross a lipid bilayer by free diffusion.
Explanation:
The new species would try and crossbreed possibly, or see them as weak and kill them off and take their resources.
True :) Acid cant burn its self.