Answer:
The original phagocyte secretes cytokines that attract other phagocytes
Explanation:
Before phagocytosis occurs and with the presence of an original phagocyte at the scratch site mostly a macrophage (also a phagocyte), chemical signals signals are given off to attract phagocytes to the scratch site.
These chemical signals may be cytokines that are given off by macrophages located in the tissue near the infection site etc. These cytokines produced can then stimulate the recruitment of phagocytes including the neutrophils and monocytes from the blood.
Yes both occur in mitocondria.
The flexible lipid bilayer that surrounds the cell and acts as a selectively permeable barrier that regulates what enters into and what exits out of the cell would be the cell or plasma membrane.