Final answer:
The plasma membrane surrounding dso proteins is most likely rich in cholesterol because it helps in maintaining membrane fluidity and integrity.
Step-by-step explanation:
Based on the hypothesized localization of dso proteins, the region of the plasma membrane that surrounds dso is most likely rich in cholesterol relative to other plasma membrane regions. This is because cholesterol helps maintain membrane fluidity and integrity by interspersing among the phospholipids in the bilayer of the membrane. This role of cholesterol in the plasma membrane is understood through the fluid mosaic model, which describes the plasma membrane as a dynamic combination of phospholipids, cholesterol, and proteins. Moreover, it is indicated that cholesterol is important for the shape of the plasma membrane and is interspersed in the core of the phospholipid bilayer, supporting the stability and fluidity of the membrane.