Vesicles form naturally during the process of secretion(exocytosis), uptake (phagocytosis and endocytosis) and transport of materials within the cytoplasm. Alternatively, they may be prepared artificially, in which case they are called liposomes.
Answer:
Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface. Permeable walls - allow gases to pass through. Extensive blood supply - ensuring oxygen rich blood is taken away from the lungs and carbon dioxide rich blood is taken to the lungs.
The answer is Physical Property
I think it’s nucleic acid