The membranes of both B cells and the cancer cells are largely composed of phospholipids. Explain how, when the membranes are fused, the polar parts of the phospholipids from one cell will interact with the phospholipids from the other cell and how the nonpolar parts of the phospholipids from one cell will interact with the phospholipids from the other cell.

The cell membrane separates the external and internal environment of the cell. The cell membrane is composed of bilayer lipids, proteins and small amount of carbohydrates.

The lipid part is soluble in hydrophobic environment or with the hydrophobic part of other phospholipids because like molecules dissolve in like molecules. The hydrophobic part is non polar and hydrophilic parts is able to dissolve in polar area due to the interaction of same molecules with each other.  

the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.