Histamine is secreted by:
1. | Mast cells | 2. | Fibroblast |
3. | Histiocytes | 4. | Plasma cells |
In higher vertebrates, the immune system can distinguish self-cells and non-self. If this property is lost due to genetic abnormality and it attacks self-cells, then it leads to :
1. | Active immunity | 2. | Allergic response |
3. | Graft rejection | 4. | Auto-immune disease |