It is possible to refer to them as such but not exactly correct. After B cells are helped by TH1 cells, the B cells differentiates in to thousands of plasma cells. The plasma cells secrete antibody's...
Yes they are
Cell membrane, cytomembrane or semipermeable membrane
Phagocytosis!
It is known as a lot of things such as the M Phase, because the "M" stands for Mitosis when the cell divides into 2 new "Daughter Cells."