Phospholipids will form a bilayer in water because they contain hydrophobic (Water fearing.. in this cause water "hating") tails and hydrophilic heads (water loving). So they form a bilayer to remove the tails from water likewise, this satisfies the hydrophilic heads because they are still exposed to water.
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:
If your question is referring to the factors limiting the growth and development of the species of deer,
Biotic:
1) Food sources like Grass
2) Predators like Wolf
3) parasites like leaches
Abiotic:
1)Temperature
2)Water
3) Pollutants in environment.
A picture is needed to answer.