Which of the following immune disorders is characterized by the immune system attacking and damaging its own body tissues?

Explanation: B cells are a type of lymphocyte that plays a central role in the adaptive immune response. When activated by the presence of specific antigens, B cells differentiate into plasma cells, which are responsible for producing large quantities of antibodies that can target and neutralize the invading pathogen.

Incorrect choices:

a. T cells are another type of lymphocyte that is involved in cell-mediated immunity, where they directly attack infected or abnormal cells. They do not produce antibodies.

b. Natural killer cells are part of the innate immune system and are responsible for killing infected or cancerous cells. They are not involved in antibody production.

d. Macrophages are phagocytic cells that engulf and destroy pathogens and debris in the body. While they play a crucial role in immune responses, they do not produce antibodies.

Explanation: Antigens are unique molecules or proteins present on the surface of cells, including pathogens. The immune system can recognize these antigens as "non-self" and mount an immune response to eliminate them while sparing the body's own cells, which display different antigens that are recognized as "self."

Incorrect choices:

b. Recognizing different blood types is relevant for blood transfusions but not a primary mechanism of distinguishing self from non-self by the immune system.

c. Monitoring hormone levels in the body is not directly related to the immune system's ability to distinguish between self and non-self.

d. Cytokines are signaling molecules released by immune cells to regulate the immune response but are not the primary means of distinguishing self from non-self.