How does the body tell the difference between its own cells and foreign cells?

December 24, 2011

How does the body tell the difference between its own cells and foreign cells?

A. Memory cells recognize different kinds of cells.
B. Foreign cells have different DNA.
C. It recognizes antigens on the cell surface
D. It cannot differentiate between types of cells

2 Responses to “How does the body tell the difference between its own cells and foreign cells?”

Peter S Says:
December 24th, 2011 at 9:03 pm
C. It recognizes antigens on the cell surface.

Eg, differences in the ABO blood groups are due to surface antigens onn the red blood cells.
Drogba Says:
December 24th, 2011 at 9:17 pm
The immune system protects the body from potentially harmful substances by recognizing and responding to antigens. Antigens are molecules (usually proteins) on the surface of cells, viruses, fungi, or bacteria. Non-living substances such as toxins, chemicals, drugs, and foreign particles (such as a splinter) can be antigens. The immune system recognizes and destroys substances that contain these antigens.